ſ º | - | He | | | HE 5'12. B assº foºt- º s t a t = O F N E B R A S K A v. D. E. P. A R T M. E. N. T. O. F. R O A. D. S. | A N. D. L. R. R. I. G A T O N me tropolit a n C. ^ - O PROPOSED TRAFFICWAY SYSTEM Zºe Z - UNIVERSITY OF MICHIGAN LIBRARIES HOWARD, NEEDLES, TAMMEN & BERGENDOFF C. C. N. S. L. L T | N. G E N G - E E R 5 KANSAS CITY, MO. NEW YORK, N. Y. WLBUR SMITH & ASSOCATES T. R. A. F. F. C C C N S U L T A N T S NEW HAVEN, CONN. State of Nebraska Department of Roads and Irrigation OMAHA METROPOLITAN AREA PROPOSED TRAFFICWAY SYSTEM VOLUME | – TRAFFIC STUD|ES October 1956 HOWARD, NEEDLES, TAMMEN & BERGENDOFF , r. Consulting Engineers Kansas City, Mo. New York, N. Y. WILBUR SMITH & ASSOCIATES Traffic Consultants New Haven, Conn. Transportatº libråty; 3. I K) - à ** ~º º 2.5 —cº ºl{#} is *g. #! b. º § Hºuſ idžić); ENOCH R. N E E D LES R U BEN N. EER GEN D OFF T H EOD ORE J. CAM E E RN ELL | S E - FAUL JOSEF SORKIN JAMES P. EXU M E. LM ER K.T 1 M BY ERN EST E. HOWARD 19 O3 - 1953 H E N RY C.TAM M EN | NACT IVE I 95 O Mr. HOWARD, NEEDLEs, TAMMEN & BERGENDoFF BOSTON, MAS SACHUSETTS C O N S U L T | N G E N G | N E E R S CLEVELAND, OHIO HART FORD, CONNECTICUT | 8 O 5 GRAND AN/ ENU E 99 C H U R C H STREET M | LWAUKEE.WISCONSIN FORT LAUDERDALE, FLORIDA KANsAs city e, Mo. NEw York 7, N.Y. T OPEKA. KANSAS LOUISVILLE, KENTUCKY PORTLAND, MANE CHARLESTON, WEST VIRGINIA KANSAs cITY 8, Mo. October 18, 1956 L. N. Ress State Engineer Nebraska Department of Roads and Irrigation Lincoln, Nebraska Re: Trafficway System; Omaha Metropolitan Area Dear Mr. Ress: For convenience in handling, the trafficway system studies for the Omaha Metropolitan Area have been compiled in three volumes, as follows: Volume I - Traffic Studies Volume II - Traffic Studies; Appendices Volume III - Street and Highway Plan Presented herewith are Volumes I and II of the stud- ies covering traffic investigations. Assembly of the data and analysis thereof, as summarized in these volumes, were executed by Wilbur Smith and Associates who had the responsibility of developing these aspects of the studies. Sincerely yours, HOWARD, NEEDLES, TAMMEN & BERGENDOFF no-º- Jos. Sorkin º illila. esmitſ and –4 scale, TRAFFIC e PARKING e TRANSIT e HIGHWAYS 495 ORANGE STREET V!ew 24a Weſt, Conn. October 9, 1956 Mr. Josef Sorkin Howard, Needles, Tammen & Bergendoff 1805 Grand Avenue Kansas City 8, Missouri Dear Mr. Sorkin: We are pleased to submit herewith our completed report on the movements of people and goods in the metropolitan area of Omaha, Nebraska. The report consists of two volumes. Volume I is a presentation and analysis of the 1955 origin-destination survey made by us, and outlines methods used to project travel to 1960 and 1970. Volume II is an Appendix containing tabulations of the basic data collected in the 1955 study and detailed trip projections for 1960 and 1970. In addition to this work we have prepared traffic assignments to a system of express highways which your firm has proposed to serve the Omaha Metropolitan Area. The Omaha traffic survey was conducted and analyzed by engineers of our staff, and we assume full responsibility for the methods employed and the data presented. Mr. Jack Darnall was our Project Director in Omaha. Mr. F. Houston Wynn originated the methods of data analysis presented here and super- vised their use. We believe that these new techniques represent basic improve- ments to the methods of travel prediction which have been used heretofore. We have enjoyed the opportunity of working with you on this very important and very interesting study. Respectfully submitted, } - * * {...,’ ” º - 'a f v/ { º W bur NEW HAVEN, CON N. e- - COLUMBIA, S. C. - - RICHMOND, VA. PART PART Omaha Traffic Studies TABLE OF CON TENTS BACKGROUND Purpose and Scope of the Origin-Desfin afion Survey Home Interview Origin-Destination Survey Future Trip Estimates Composition of Survey Area Population Vehicle Registration Economy Transportation Region Previous Studies of Omaha Area Traffic Counting Program 1948 Traffic and Parking Sfudy 1944-1945 Origin-Destination Survey TRAFFIC CONDITIONS 1955 Traffic Volumes Volumes of Principal Streets Volumes on Bridges Pattern of Hourly Traffic Demands Quality of Flow Regulations and Controls Average Traffic Time Speed and De lay Traffic Accidents Street Sufficiency in Central Business District Page . 17 17 17 20 2] 21 25 25 27 27 27 PART PART IV Major Traffic Generators The Central Business District Secondary Business District Stockyards Offutt Air Force Base Others THE ORIGIN-DESTINATION SURVEY The Dwelling Unit Sample Truck and Taxi Samples Roadside ln terview Sample Methods and Coverage of the 1955 Study The Home-ln terview Survey The Truck Survey The Taxi Survey The External Survey Data Obtained Reliability of Data - Vehicle Trips Auto and Trans if Passengers Trip Desires in Omaha Metropolitan Area CHARACTERISTICS OF TRAVEL IN THE METROPOLITAN AREA The shape of the Future City Labor Force in Metropolitan Area Employment in Each Zone Automobile Ownership Trip Length and Travel Time Characteristics of Internal Trips Trips Generated in the Central Business District Work Trips Non-Work Trips Page 33 33 35 35 36 36 37 37 39 39 41 42 43 43 43 45 46 47 49 6 l 61 62 62 63 64 64 66 66 69 Infra-Zone Trips 70 PART V Work Trips Generated Outside the Central Business District Work Trips by Labor Force Work Trips Generated by Employment Infra-Zone Work Trips Non-Work Trips Generated Outside the Central Business District Infra-Zone Non-Work Trips Trips By Commercial Vehicles Infra-Zone Truck Trips Characteristics of External Trips Through Trips Area Tributary to Omaha Internal Distribution of External Trips External Trips in Central Business District TRAVEL IN OMAHA METROPOLITAN AREA 1960 AND 1970 Future Study Area Projections of Population Distribution Transportation Facilities - 1970 Metropolitan Area Travel - 1970 Mode of Travel Purpose of Trip Central Business District Trips Work Trips Non-Work Infra-Zone Trips External Trips by Omaha Residents Total Trips Truck Trips Distribution of Internal Trips External Area Trip Volumes at External Cordon Internal Distribution of External Trips Page 7] 72 75 76 77 77 78 8] 82 83 85 88 89 90 90 9] 94 96 97 98 98 99 100 | 00 | 00 | 00 | Ol | 02 106 | 12 | 12 Table Table Table Table Table Table Table Table Table Table Table Table Table LIST OF TABLES Population Trends for States of Nebraska and low a dnd for Cities of Omaha, Council Bluffs and Omaha Metropolitan Area, 1900-1970 Vehicle Registrations for State of Nebraska and Counties of Douglas, Sarpy and Pottawattamie, 1940-1955 Trips Info, With in and Through Survey Area, 1944-1955 Traffic Trends at Fifteen External Cordon Stations Average Weekday Traffic on Missouri River Bridges Average Weekday Volume and Per cent of “Through’’ Traffic over Missouri River Bridges Trips to and From Central Business District Trip Reports Obtained from Interviews External Termini of Local Trips Crossing Omaha Cordon - 1955 Through Trips - 1955 Travel by Residents of Study Area Average Number of Trips per Day Per Dwelling Unit — 1955-1960-1970 Growth Factors Applied to Projection of External Travel at Omaha Standard Metropolitan Area Limits. Estimated Traffic Volumes at External Station Groups at Omah a Standard Metropolitan Area Limits Page 20 22 34 46 82 83 97 | 10 | 13 fº =e a ºs º- Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure LIST OF FIGURES tan Area Area Map Regional Map Traffic Flow Map - Nebraska Rural State Highways in Omaha Area Traffic Flow Map of Major Arterial Streets - 1955 Traffic Flow Map of Central Business District - 1955 One-Way Street Pattern - 1955 Bus System, Omaha Hourly Pattern of Passenger Cars and Trucks Expressed as Per Cent of Average Hour of Day Traffic Signal Locations - 1955 Peak-Hour Passenger Car Travel Time in Minutes Between Central Business District and Zone Centroids (Weekday - 1955) Off-Peak Passenger Car Travel Time in Minutes Between Central Business District and Zone Centroids (Weekday - 1955) Speed-Delay Runs on Four Major Arterials (Peak-Hour) Page | ] | 2 13 15 16 23 26 28 29 30 Figure 14. Figure 15. Figure l 6. Figure 17. Figure 18. Figure 19. Figure 20. Figure 21. Figure 22. Figure 23. Figure 24. Figure 25. Figure 26. Location and Number of Vehicle Accidents - 1955 Map of Metropolitan Omaha showing Traffic Survey Tracts, Zones and External Stations - 1955 Zone Map - Douglas and Sarpy Counties, Nebraska Zone Map - Pottawattamie County, low a Screen Lines - 1955 Combined North and South Screen Lines - Passenger Cars Present Desire Lines of Internal Travel Exclusive of Central Business District Present Desire Lines of Internal Vehicular Traffic Travel to Central Business District Present Desire Lines of External–Internal Travel Present Desire Lines of Through External Travel Present Desire Lines of Passenger Car Driver Trips To and From Central Business District Present Desire Lines of Passenger Car Drivers Exclusive of Central Business District Present Desire Lines of Transit Riders To and From Central Page 31 38 40 4l 44 45 48 50 5] 53 54 56 Business District 58 Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure 27. 2 8 29. 30. 3 l. 32. 33. 34. 35. 36. 37. 38. 39. Present Desire Lines of Transit Riders Exclusive of Central Business District Present Desire Lines—Aii Work Trips Generated in Central Business District — All modes Proportion of Work Trips To and From Central Business District by Transit Non-Work Trips Generated in Central Business District — All Modes Proportion of Non-Work Trips To and From Central Business District by Transit Work Trips To and From Places of Residence Proportion of Work Trips Made by Transit Trips To and From Places of Work – All Modes Non-Work Trips — All Modes Non-Work Transit Riders – Per Cent of Inter-Zonal Movement by Transit Versus Peak-Hour Transit Time from Central Business District Truck Trips Generated Between Residential Populations Versus Travel Time Truck Trips Generated by Industry and Employment Page 59 67 68 70 7] 73 74 75 76 78 79 80 Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure 40. 41. 42. 43. 44. 45. 46. 47. 48. 49. 50. 5] . 52. External Auto Trips Generated by Omaha Metropolitan Area External Truck Trips Generated by Omaha Metropolitan Area Internal Distribution of External Trips at Cordon Population and Car Registration Trends Omaha Standard Metropol- itan Area. Peak Hour Passenger Car Travel Time Between CBD and Zone Controls (Weekday 1970) Auto Driver Trips To and From Central Business District 1970 Transit Riders To and From Central Business District 1970 Auto Driver Trips Between Internal Zones Exclusive of Central Business District 1970 Transit Riders Between Internal Zones Exclusive of Central Business District 1970 Truck Trips Between Internal Zone's 1970 Auto Driver Trips External Stations and Peripheral Zones To and From Central Business District 1970 Auto Driver Trips External Stations and Peripheral Zones To and From Internal Zones Exclusive of Central Business District 1970 Truck Driver Trips External Stations and Peripheral Zones To and From Internal Zones l 970. Page 84 86 87 93 103 105 107 | 08 | 09 | ]] | | 5 | | 6 | ||7 PART 1 BACKGROUND This report describes and summarizes the results of a comprehensive origin- destination survey conducted through out the Nebraska portions of the Omaha Metropolitan Area in the fall of 1955. The survey was authorized and financed jointly by the City of Omaha, Douglas and Sarpy Counties, the Nebraska Department of Roads and Irrigation, and the U. S. Bureau of Public Roads. Purpose and Scope of the Origin-Destination Survey An origin-destination survey similar to that described in this report was made in Omaha in the fall of 1944. The travel information developed in the earlier study has been of much use to highway and planning agencies, despite the fact that the survey was made under war-time conditions at a time when gasoline rationing and other restrictions were imposed upon the normal use of private automobiles. When this study was undertaken, the 1944 data were l l years out of date. A great deal has happened to the transportation picture in the intervening time. This new study updates the older survey and provides a firm basis for planning the new facilities which are presently being studied and programmed. The most immediate use for the new study will be to provide essential traffic information for the location and design of express highways and major arterials in the Omaha Metropolitan Area. The need for a major highway plan is urgent. Traffic conges- tion with in the City of Omaha is becoming increasingly acute. The Metropolitan Area is expanding and vehicle registration has virtually doubled since 1944. There is every evidence that these trends will continue. Another major reason for undertaking a traffic survey now is the urgency with which state and federal agencies are pressing for completion of the Interstate high- way system. During the past year the Bureau of Public Roads has approved the general location of the urban sections of the Interstate highway system through and around the Omaha Metropolitan Area as shown in Figure 1. City, county and state agencies are currently active in the development of a master plan of highways for the Omaha area. In order that the master plan be based Upon full knowledge of existing and potential traffic conditions, the data contained in this survey will be used to guide its develop- men f. Home-Interview Origin-Destination Survey — The home interview type of origin- destination survey provides a more complete picture of urban travel than any other data collecting technique in common use. The home interview study combined with an external cordon survey and special truck and taxi studies obtains significant information on every phase of urban vehicular travel. The data thus made available show not only the amount of travel that is performed by automobile and trucks but indicate the number, direction and purpose of persons making trips as vehicle drivers or auto and transit Passengers. These facts provide indication of potential auto travel as well as inform a- tion concerning the volume of movement presently made by auto drivers. This inform a- tion is essential if the future travel patterns in the Omah a community are to be correctly projected. Future Trip Estimates – An especially important part of this report is the section devoted to the derivation of future travel patterns in the Omaha Metropolitan Area. A conscientious effort has been made to relate future travel to probable future land use. In order to do this, the 1955 trip data have been related to rates of travel between populations of various types – persons, families, labor force, automobiles, and employment. The modifying influences of trip length (travel time), I and use, trip purpose, and mode of travel have also been taken into account in developing relation- ships which are consistent and reliable enough to use as trip predictors. The estimates of future travel which are presented here are closely related to the behavior characteristics of the Omah a populace. They are based on reasonable disciplines and should prove to be far more reliable than the extrapolations of historical data which are often the bases for future estimates. The uses of these data for planning purposes are manifold. Their most immediate use will be to designate the amount of travel likely to take place on proposed express highways. The Metropolitan Area has been subdivided into a system of zones WASHINGTON co, Douglas Go TV to sloux city, Iowa COUNCIL BLUFFS º - l º RALSTON | Doug AS Co. -- RVER SARPY CO. Sºssº–s TO SAINT N JOSEPH, MO. * - Pottawa ſame co MILLS. Too Figure 1 GENERAL LOCATION OF INTERSTATE HIGHWAY SYSTEM INOMAHA METROPOLITAN AREA OMAHA TRAFFIC STUDIES --- O 1 2 3 4 5 SCALE IN MILES WILBUR SMITH 8 ASSOCIATES Figure 2 AREA MAP OMAHA TRAFFIC STUDIES O 2 3. 4. 5 SCALE IN MILES - ------------ wil-BUR SMITH & ASSOCATES so that origins and destinations of travel can be more or less pinpointed. The origin- destination dota have been summarized to find the amount of movement faking place between every possible zone-pair within Omaha. When new expressway routes have been designated, a reasonable pattern of use can be worked out for each facility. The Probable volume of use on each segment of express highway will provide a basic crite- rion for the standard of design which will be established at the time the facility is built. Composition of Survey Area The area included within the limits of the Omaha origin-destination survey is somewhat greater than the Nebraska portion of the “urbanized area” defined by the Bureau of Census. This urbanized area is but a small portion of the “Standard Metropol- ifon Area’’ which consists of Douglas and Sarpy Counties in Nebraska and Pottawattamie County in Iowa. The urbanized area defined in the 1950 census was not used to estab- lish the limits of the origin-destination survey area because urbanization has now grown beyond the 1950 boundary. An arbitrary boundary was therefore established to define the survey area as shown in Figure 2. Population – The City of Omaha contained nearly 70 per cent of the total population in the Standard Metropolitan Area in 1950. The 1950 population within Omaha was 251, 117 while the Standard Metropolitan Area population a mounted to 366,365 as shown in Table 1. The 1955 population with in the origin-destination survey area was estimated at 296,449 persons at the time of the study as shown in Table 3. Vehicle Registrations – Table 2 indicates the rapid increase of vehicle registrations in the Omaha area in recent years. The 1955 registrations of cars and trucks in Douglas and Sarpy Counties totaled 122,728, of which 106,703 were passenger cars and 16,025 were trucks. This marks an increase over 1940 of 88 per cent and is about double the number of vehicles in service at the time of the 1944 survey. The 1955 total vehicle registration for the State of Nebraska was 58 per cent greater than 1940. Douglas County's registration amounts to 17 per cent of the State's total. Although the traffic study area was not extended east of the Missouri River into Iowa, the trend in motor vehicle registration in Iowa, especially in Pottawattamie Table Omaha Traffic Studies POPULATION TRENDS FOR STATES OF NEBRASKA AND LOWA and for Cities of Omaha, Council Bluffs and Omaha Metropolitan Area 1900-1970 Omaha S Omaha Standard Year Nº. º: sº of (Present Council Metropolitan S K Cl OW Cl City Limits) Bluffs Area (4) L 1900 1,066,300 2,231,853 102,555 25,802 204,006 1910 1, 192,214 2,224,77 l 124,096 29,292 233,652 1920 1, 196,372 2,404,02 l 191,60 l 36, 162 275,444 1930 1,377,963 2,470,939 214,006 42,048 313,272 1940 1,315,834 2,538,268 223,844 41,439 325, 153 1950 1,325,510 2,621,073 251, 117 45,429 366,365 1955) 1,381,000 2,692,000 278,000 49,500 400,000 1960 1,404,000? 2,704,000? 297,000 54,000 435,000 1960 1,393,000° 2,684,000° - - - ºr * - - Be - tº E- - 1965 1,437,000? 2,762,000? 310,000 59,000 480,000 1965 1,407,000° 2,706,0003 = - - tº = - - as * * * * 1970 ¥ }: 315,000 64,500 515,000 * No. Estimate I . Bureau of the Census -- “Current Population Reports, Population E stimates’’, Series P-25, No. 129 2. Bureau of the Census -- “Current Population Reports, Population E stimates'' Series P-25, No. 1 1 0 -- Component Method, Series A & B (1940-53) 3. Same report referred to in? -- Component Method, Series C (1940-53) 4. Bureau of Census Definition — Includes Douglas and Sarpy Counties in Nebraska and Poff a waffamie County in Iowa. - 6 - : Year 1940 1945 1947 1948 1949 1950 195] 1952 1953 1954 1955 Year 1940 1945 1947 1948 1949 1950 195] 1952 1953 1954 1955 VEHICLE REGISTRATIONS FOR STATE OF NEBRASKA and Counties of Douglas, Sarpy, and Potta w attam ie, 1940 - 1955 Table 2 Omaha Traffic Studies State of Nebraska Passenger Cars 347,515 330,614 369,846 394,652 420,31 l 441,632 467,445 472,443 480,343 483,839 503,362 Trucks 68,016 76,273 98,296 110,983 l 19,473 125,447 138,43 l 142,90 l 142,999 145,806 150,809 Sarpy County, Neb. Passenger Cars 3, 36 l 3,509 3,891 4, 4 lº 5, 18 l 6,00l 7, 132 6,972 6,766 7,712 8,674 Trucks 742 719 l Comparative County Registration Data un available for years 1941-1944 and for 1946. 875 1,010 1,055 l, l 24 l, 30 l 1,324 1,398 1,419 1,55] Douglas County, Neb. Passenger Cars 54,902 49,700 57, 167 61, 209 67,886 75,963 81,891 85,778 89, 204 90,721 98,029 Passenger Cars l6, l 15 13,856 16,293 17,540 19,550 21,620 22,529 22,897 23,84l 24,802 26,320 Trucks 8,010 7,858 10, 192 11,349 1 1,664 12, 21 l 13, 163 13,940 13,450 13,664 14,474 Poffa waffamie County, low a Trucks 2,367 2,297 3,096 3,494 3,770 3,984 4, 21 l 4,320 4,468 4,624 4,742 Number of persons residing in area Omaha Trips Into, Within and Through Survey Area, 1944-1955 2 Number of cars owned in area All trips in area on average weekday All auto, truck, and taxi driver trip s A || infernal trips - all modes Auto and taxi driver trips Truck driver trips Auto, truck, and taxi passenger trips Transit rider trips Table 3 Traffic Studies External trips with internal Origin or Destinction Through trips (neither Origin or Destination in area) l. Auto driver trips Truck driver trips Auto driver trips Truck driver trips 1944 data do not in clude the low a portion of the study are a 3 1944] 227,974 41,836 389,107 l66,388 369,763 125,086 21,958 64,788 157,931 18,521 13,851 4,670 823 475 348 1955 296,449 83,775 691,029 463,721 630, 176 330,874 71,994 | 49,075 78,233 54,987 45, 159 9,828 5,866 4,858 l,008 2. No. of persons and No. of cars determined from the dwelling unit sample in each year 3. 1944 external trips were adjusted to include travel between Omaha and Council Bluffs | County directly east of Omaha, is closely related to the areas's registration index. The neighboring low a county showed a 1955 vehicle increase over 1940 of 68 per cent, while the State of lowa's vehicle registration for the same period increased only 46 per cent. Relating passenger car registration in Douglas County to population discloses a steady reduction in the ratio of persons to cars. In 1940, there was only one car registered for every 4.5 residents in the County. in i950, ihe afio was reduced to one car for every 3.7 persons. In 1955, the ratio had become one car for every 3.2 persons. The home-interview phase of the traffic study area involving the Douglas and Sarpy County portions of Metropolitan Omaha took in to account a passenger car registra- tion of 83,775. This amounts to 3.5 persons per car in the study area. Economy – Omaha's economy has traditionally been based upon the agriculture of the region that it serves. However, in recent years, more and more manufacturing has contributed to an industrial economy with an in creasing amount of non-agriculture in- dustry tending to broaden the economic base. In 1955 there were over 600 manufacturing establishments in the Omaha area, employing about 40,000 persons and doing an annual business of approximately $l.25 billion. A large share of this manufacturing industry is related to meat packing in which Omaha leads the whole United States. Non-agricultural industry in the Omaha area is related principally to structural steel and foundry products, clothing manufacture, chemical manufacture, and a rapidly expanding variety of small electronic, medicinal, and miscellaneous products. Transportation – Omaha is a crossroads for highway transportation. The city is located at the junction of several U. S. numbered Highways. U. S. Route 6 and U. S. Route 30-Alternate are principal east–west high ways through the Omaha area. North- south traffic is served by U. S. Route 73 and U. S. Route 75. The city is also a center of railroad transportation and is served by ten different railroad lines. Air travel to and from Omaha is assuming in cre a sing importance each year. Barge traffic is an important means of moving goods on the Missouri River and is continuing to increase at a steady rate. The Missouri River channel is currently being deepened and widened to encourage additional movement of goods by water. Region – Omah a dominates a large agricultural community with relatively little competition within a radius of more than one hundred miles. The city's principal competitors are Kansas City, about 200 miles to the south; Minneapolis–St. Paul, more than 400 miles northeast; Denver, Colorado, about 550 miles west; and smaller cities including Lincoln, the capital city of Nebraska, 58 miles southwest; and Des Moines, capital city of lowa, 136 miles to the east. A regional map is shown in Figure 3. Previous Studies of Omaha Area Omaha's traffic problems have in creased rapidly over the past two decades. During this period more and more attention has been given to traffic values and the accumulation of information on traffic behavior in the city and surrounding counties. Traffic Counting Program — For many years the Nebraska Department of Roads and Irrigation has collected traffic counts each year on the principal state highways and other main roads throughout the state. At intervals the se data are accumulated and prepared in traffic flow map form; thus, a record exists showing the volumes of travel on the highways which approach and pass through Omaha and the counties adjacent. An example of the most recent of these flow maps is shown in Figure 4. Traffic counts have also been made in the City of Omaha. Traffic flow maps have been prepared on two occasions. A city-wide survey was conducted in 1937-38 including a detailed section map of the Central Business District. Again, in 1944, at the time of the earlier origin-destination survey, many traffic counts were accumulated. In 1948 a traffic and parking study was made which resulted in a traffic flow map of the downtown area. The most recent map is that prepared in the course of the present survey which is shown in Figures 5 and 6. 1948 Traffic and Parking Study – The 1948 traffic study was reported in 1949 and has led to numerous improvements in downtown traffic operations. On-street parking was streamlined, with more spaces provided for truck loading and unloading. Curb parking time limits were shortened and much new off-street parking recommended. A considerable amount of off-street parking has been provided as a direct result of the study. The one-way street program as shown in Figure 7 also grew out of these inves- tigations. - 10 - - - º - - K. ST. SNPººl. O-O *E*otº 16 º Al-BERT LEA SIO 16 |OUX - º Fººt's L-º- MINNESO - - * * - - OWA / 17 59 lº º --- 77 SIDAKOTA - NEBRASKA 7 - º - º - SOUX - 2O CITY WATERLOO 2O - 2O º º 103 275 AME 30 73 w 77 - | º 2. 39 DES MONE'S º - º º ºf 153. NORTH () - PLATTE GRAND 3 O - ISLAND A. OMAHA COUNCIL BLUFFS S-º- | - | NCOLN L- º ſº 34. 6 \ - 30 - 6 OWA º - - MISSOUR HASTINGS º 7 Sº - NEBRASKA 36 | KANSAS º ST - - - - JOSEP 36 7- º º- Gº 24 -- KANSA - -- CTY º SALNA TOPEK A KANSAS CITY 4C) 40 -- --- 5 77. Figure 3 -50 - - 5. - *- REGIONAL MAP #: -> OMAHA TRAFFIC STUDIES 51s - 54. 3- == 50 75 do - SCALE IN MILES W. C. H. Tº SPRING- 69 F. E.L.D WILBUR SMITH 8 ASSOCIATES - ------- -- r TRAFFIC SCALE |- P-P-L-ion- Figure 4 - * TRAFFIC FLOW MAP THousands of vehicl E5 NEBRASKA RURAL STATE HIGHWAYS |NOMAHA AREA OMAHA TRAFFIC STUDIES WILBUR SMITH 8 ASSOCIATES 1944-45 Origin-Destination Survey – One of the first of the home-interview origin-destination surveys was made in Omaha in 1944 and 1945 under the auspices of the Nebraska Department of Roads and Irrigation and the Bureau of Public Roads. Despite the fact that this survey was undertaken during war-time when gas rationing and other restrictions reduced the potential amount of automobile travel, a great deal was learned which has contributed to a basic understanding of Omaha's traffic problems. The area of study in the 1944-45 survey included Council Bluffs, Iowa, and all of Urban Omaha. The Nebraska portions of the survey area were somewhat smaller than the area studied in the 1955 investigation. Although the two origin-destination surveys do not cover precisely the same areas, some comparable statistics shown in Table 3 are of interest. The residents of the Metropolitan Area studied in 1944, not including residents of Council Bluffs, made a total of some 370,000 trips of all types (including travel by truck and taxi drivers). In the 1955 study the number of trips made entirely within the study area amounted to about 630,000 or approximately 70 per cent more than were accounted for in the 1944 study. - 12 - Figure 5 TRAFFIC FLOW MAP OF MAJOR ARTERIAL STREETS 1955 OMAHA TRAFFIC STUDIES - - - = O | 2 3. SCALE IN MILES - Sº ------ -------- ----- --------- alº- WILBUR SMITH 8 ASSOCIATES - - - º - - º - - TREET - - - STREET STREET STREET Figure 6 TRAFFIC scALE TRAFFIC FLOW MAP OF CENTRAL BUSINESS DISTRICT 1955 ſaveRage 24-Hour weekly-1955) OMAHA TRAFFIC STUDIES WILBUR SMITH 8 ASSOCIATES Total TRAFFIc In 1944 about 55 per cent of the person trips (auto driver, auto passenger, transit) performed in the city by residents was made by auto drivers and auto passengers; in the more recent study nearly 85 per cent of all the person trips performed in the city were made in cars as drivers and passengers. In the 1944 study 45 per cent of all internal person trips took place on street cars and buses. In the 1955 study only 12 per cent of all internal travel was made via mass transportation. Figure 8 illustrates the present bus system in Omaha. In 1944 vehicles (automobiles, trucks and taxis) performed nearly 166,500 frips into, within, and through the Omaha study area (not including the Council Bluffs portion of lowa). In 1955 vehicle trips performed in the area were almost three times this number, accounting for approximately 464,000 movements of all types. About 402,000 (87 per cent) of these trips were made entirely within the Metropolitan Area. In the 1944 study approximately the same proportion, 147,000 trips, or about 88 per cent, was generated entirely within the cordon. 's- LAKE ST. A. l. l. cum-Inc. st. Eun-T ST. w EastER ST. Cass sº. d > - an ºr u - ºr - - | DODGE ST = | ºiſi I. 4. ! E. St. MARYS Hº- r −T LEAVEN worth- ST. |* ! º Figure 7 T-T^. ^. - L- º º CAL FOR-A. St. º CAPITOL || || || || || || || | | || || || || || || || Ave. : :: :==º: ...] […] [] [] [] [ _ U * [] [ ] | JACK SON ST. , , ,-,-, *- : T . º º ** Fº: ONE-WAY STREET PATTERN 1955 OMAHA TRAFFIC STUDIES WILBUR SMITH 8 ASSOCIATES - sº - º ------------- º - ---------------- - - --------- ------- - --------------- -----ee--" - -------------- - --> ºnes" Tº -- - ------------- - - * ---------------------- --------- - --------------------- - - - ---------- -- - Lº * : ------------ 23 ºn- ºr . --- ºr - - - - --------- º ------ - -------------- rº -- --------- --- -- º - -------- Fºº-º- --- -- - - - ----------------- - - ------------------------ --------------------------------- -- -------------------------------- ----------------------------- - ------------------------- ſ F---------- -- - ----------------- --- ------ --- ---------------------------------- -- -------------------- -- - - - - - - - - - ------- ------ ºn------ --- 2- - º N NEBFasº. ---> -- ºw- º º - - º * * * º --------- *ºº --- º ------ ºn--- * º -- --- - - - -- - - - - - º - - - 28. , E. º - - - -- - º - - - - - - E. 30 - ºn ------- - - - - - º - - ------- --- - - - - - - - - - - - - - º __ - ºl. ------ - - ! - - - -------------------------------- * * | º - --- - ----- - - = g : g 4.- : Ti º - * 1: 5 º - H - | alones -lº ºr " - º +: --- 2a----- -: Gº - º 20 & 9 s ºf sº - - * º - 2- - - - - -- - - -: -------- | º - - -- -- - - - - ---. º º - º º 33 - - * * * : *nºt as sº º 5. ----- - - - -- - wºol as sº 5 sº ----- -- undeswood ave - |Bºº sº T - --- - cº, sº = 2. KEY TO ROUTES - 2–ºf– ºl-1-2 *** * ºcese sº MA IN LINES TTE ------------------- SEE ---- FEEDER LINES º F- --- - -- Insest - RUSH HOUR ONLY -- ------ - - - - ----- sº ECIAL SCHOOL SERVICE - º sº wº leavenwoºtº st - _* - - - º T == ---- - - -- º * *ºa - ------- - * 1 º º º ------- - - - 22 * - Laºs. ----- -------- - - --- -º-º-º-a- º 22. 2- - -- º - * = e! - - ------- - - - = ** : *-* | * * , - * * * * --- - - cepa, sº . . " -- |-2s--- ***** - 2- - * * --------- r- - - - ------- ºr --- 29 | - - - - - ****** * * 22 ". º - * * * - cenres st---- = º º - ------- *s -- * ------- Sºo- º 29 º: ------ ---------- - - ----- - - - Larsenescº -- º: º 6- Davenport st. ------- ºr º: º -- - - - - - - - - - - - - ----- *--- ~~--- tl ºr - - º ------- º - boose .** *29 - 5 º - - ºil 2++=2-1 \ - - - º ...l.º.º.º.º...?". -- : F ºn 2 ===F2'-º', ; - - ----------------------- º - º - - - T. - E. : -- ----------------------- -- sº- Fasnam lºste & - - --------------------------- ºr--- |-3-8-1-H+++ - - -- ---------------------------- ºt. - º ------------------------------- ºn ...........º.º.º......... - --------------------------- list 1–3––– - ------------------- * ---------- -- - - ---------------------------- - - - |- -- - - - --~~ -- ----- - - - -- -----------------nu- º T- ----- - -------- - | -- ----------------------- -g ----- - ----- - º - -- ------------------------ - º - -------- ------------ - - ºl - º -: - - - - - - - - ------------------------------------- --- º: . º º DOWNTOWN AREA -------------------- - - º L-º-º: . - - - - - ----------- * - -º-º: - ** * - - -- - * -- - - - - - ------ Hº- -- *-------- - Figure 8 BUS SYSTEM, OMAHA OMAHA TRAFFIC STUDIES WILBUR SMITH 8 ASSOCIATES PART || TRAFFIC CONDITIONS 1955 The origin-destination survey has obtained trip information from a cross to develop of er measures of the traffic environment to which the origins and destina- tions are related. The se are measures of street capacifies and deficiencies; of average driving and riding speeds; of the type and amount of delay commonly experienced; of the daily and season al fluctuations in traffic demand. Traffic Volumes For many years the Nebraska Department of Roads and Irrigation has main- fained traffic counting stations on principal highways in the Omaha area. Fifteen of the 19 origin-destination stations on the Omaha external cordon in Nebraska were located at counting stations which had been operated frequently since 1937. Traffic counts made at these locations present an accurate picture of the external traffic growth as it has affected Omaha in recent years. Data for the 15 stations combined are shown in Table 4. Traffic flows on highways radiating from Omaha are shown graphically on Figure 4. Traffic volume records for travel with in Omaha are not readily available. A comprehensive series of traffic counts were made during the course of the origin- destination survey from which the traffic flow map was prepared. Figure 5 shows the relative volume of flow on principal arterial highways in the city. All flow bands represent average 24-hour weekday volumes of total vehicles. A very detailed series of traffic counts were obtained for Central Business District travel during the course of the origin-destination survey. This information is shown graphically on Figure 6. Traffic flows are heaviest on radial arterial highways serving the Central - 7 - Business District and on streets within the Central Business District. These are the traffic ways to which the greatest attention is being given to improve the quality of traffic operations and which will benefit most from new Urban highway construction. About 15 per cent of the vehicles on principal radial streets are trucks and buses. Within the industrial districts adjacent to the Central Business District such traffic approaches 20 per cent of the total. About 12 per cent of Ak-sar-ben Bridge traffic is made up of trucks, while more than 23 per cent of the South Omaha Bridge users are trucks, many of them cattle trucks destined to the Stockyards. From 20 to 30 per cent of the commercial traffic is made up of large units – truck-trailers and tractor-semi combinations — which contribute heavily to traffic congestion because of operating characteristics which are essentially incompatible with the operation of passenger cars and other light-weight vehicles. Volumes on Principal Streets – Dodge, Douglas, Farnam, Harney, St. Marys and Leavenworth Streets are the main east–west arterials in the vicinity of the Central Business District. The only eastern outlet is afforded by the Ak-sar-ben Bridge, an extension of Douglas Street. Twenty-four hour week day volumes on Dodge Street in Table 4 Omaha Traffic Studies TRAFFIC TRENDS AT FIF TEEN EXTERNAL CORD ON STATIONS Total Average Daily Traffic Average Annual Increase Year. af 15 Stations (compounded) Per cent of 1937 1937 13,879 100.0 | 1.5% 194] 21,370 l 54.0 1.6% 1948 24,075 - 173.5 6.8% 1953 33,470 24 l.2 6.5% 1955 37,890 273.0 - 18 - 1955 ranged from 2,700 vehicles on the section east of Eleventh Street to 13,000 on the section west of Twenty-fourth Street. Dodge Street is a one-way arterial for westbound traffic flow. One block south of Dodge Street is Douglas Street, a parallel ling eastbound arterial whose 1955 volume ranged from a high of 19,300 vehicles on the section near Ninth Street to a low of 9,500 near Sixteenth Street. Farnam Street, another westbound facility, carried 1955 volumes increasing from 2,400 vehicles per day at Ninth Street to 9,800 at Twenty-fourth Street. Harney Street, Farnam's eastbound companion facility, developed a high volume of 12,500 at Twentieth Street, which reduced to 3,500 at Tenth Street. St. Mary's Avenue, one-way between Howard Street at Seventeenth Street and Leavenworth Street at Thirty-first Street, carried a volume of 11,500 vehicles west of Twentieth Street and 10,000 at Twenty-fourth Street. Leavenworth Street, an east-west arterial, serving the southern part of the Central Business District, developed 1955 volumes ranging from 4,000 vehicles at Thirteenth Street up to 10,500 at T wenty-fourth Street. Several north-south arterials are also important traffic ways. South Thirteenth Street, south of Farnam Street, carried 16,500 vehicles and maintained a fairly high and constant volume all the way to Missouri Avenue on the approach to the South Omaha Bridge. The section of Thirteenth Street north of Missouri Avenue served a 1955 Average Daily Traffic of approximately 13,600 vehicles. Sixteenth Street leading north from the Central Business District was found to develop a weekday volume of 7,000 vehicles in the vicinity of Locust Street. Twenty-fourth Street serving South Omaha and the Stockyards area, carried 10,500 at Dodge Street, 6,800 at Leavenworth Street, 7,600 at Vinton Street and 5,500 at “Q” Street. North Twenty-fourth Street at Cuming Street accommodated 10,300 vehicles; volume using the street decreased to 1,300 near Ames Avenue. The newly constructed Abbott Drive connecting Omaha's Central Business - 19 - District and the Municipal Airport was found to carry a 1955 daily weekday volume of 4,000 vehicles. Also comparatively new, the Northwest Radial leading to northwest Omaha, Benson, and Irvington, carried a volume of 12,800 vehicles near Maple Street. Its two one-way access and egress arterials of Cuming and Burt Streets near Twenty-fourth Street carry volumes of 12,900 and 8,700 vehicles, respectively. Seventy-second Street, which has many of the characteristics of an outer-belt circumferential, was found to serve an average weekday volume of 8,300 vehicles in the vicinity of Dodge Street. “L” Street, an east–west street carrying circumferential movement in the south part of Omaha, was used daily by 10,800 vehicles in the vicinity of Thirty-third Street. Volumes on Bridges – Four Missouri River bridges serve Omaha. Most important of these is the Ak-sar-ben Bridge which connects downtown Omaha with Council Bluffs, low a. Average daily traffic volume on this bridge at the time of the Table 5 Omaha Traffic Studies AVERAGE WEEKDAY TRAFFIC ON MISSOURI RIVER BRIDGES, AUTUMN, 1955 Bridge Passenger Cars Trucks Total Ak-sar-ben Bridge 20,719 2,859 23,578 South Omah a Bridge 5,418 l,646 7,064 Mormon Bridge l,514 206 1,720 Bellevue Bridge 96 8 104 Total Four Bridges 27,747 4,719 32,466 - 20 - origin-destination survey amounted to 23,578 vehicles. This was more than 70 per cent of the 32,466 vehicles accommodated each day by all bridges. Average daily use of each bridge is shown in Table 5. Through trips appear to make up a relatively large share of trans-river traffic, as defined in the origin-destination survey on the bridges. Nearly one-fifth of the pas- senger cars and about one-sixth of the trucks represent trips which have neither origin nor destination in the Omaha study area. Details on through movement at each bridge are shown in Table 6. About half of the through trips reported on the bridges have origin or desti- nation in Council Bluffs or other immediately adjacent areas and should be considered local in character. Pattern of Hourly Traffic Demands – The hour from 5:00 to 6:00 P.M. was found to constitute the period of heaviest traffic flow on the average weekday. This behavior is consistent with findings in most other cities. A morning peak-hour of some- what less intensity occurred between 7:00 and 8:00 A.M. Based on traffic counts made at control stations near the Central Business District cordon the afternoon peak-hour was 11.8 per cent of the total 24-hour travel. The morning peak accounted for only 7.6 per cent of the daily trip volume. Commercial travel did not peak at these hours of heaviest total traffic demand. Approximately 10.2 per cent of the daily fruck movement was found to take place in the hours 2:00 to 3:00 P.M. The peak-hour rate of travel was fairly well sustained through out the 3-hour period from 2:00 to 5:00 P.M. Maximum commercial travel in the morning hours amounted to 8.6 per cent of the day's volume between 10:00 and 11:00 A.M. The hourly pattern of over-all traffic dem and throughout the study area is illustrated in Figure 9. Data for autos and trucks are recorded separately. Quality of Flow There is no doubt that traffic frequently becomes congested at many locations in downtown Omaha and on key radial arterials which serve the Central Business District. - 21 - Table 6 Omaha Traffic Studies AVERAGE WEEKDAY VOLUME AND PER CENT OF Over Missouri River Bridges \\ THROUGH’’ TRAFFIC % of % of Through Passenger Passenger Bridge Passenger Cars Cars Cars Ak-sar-ben 2,810 13.6 10.1 South Omah a 1,376 25.4 5.0 Mormon 3 |4 20.7 l. 1 Bellevue 44 45.8 0.2 To to 4,544 16.4 % of % of Through Truck Truck Bridge Trucks Volume Volume Ak-sor-ben 48 | 16.8 10.2 South Omah a 370 22.5 7.8 Mormon 36 |7.5 0.8 Bellevue 2 25.0 × Total 889 18.8 Total % of % of Through Bridge 4-Bridge Bridge Vehicles Volume Volume Ak-sar-ben 3,291 14.0 10. I South Omah a 1,746 24.7 5.4 Mormon 350 20.3 |. l Bellevue 46 44.2 0. I To fal 5,433 16.7 •ºr Less than 0.1 per cent Note: A bout half of the ‘‘through’' trips on the M is souri River Bridges have origin or dest in a tion in Council Bluffs and adjacent coin munities and should be considered “local” in character. - 22 - | º \ - º º #| |> #| || | 5|| || \ \ A. | º * * * * ſº a 2 : A.M. NOON Figure 9 HOURLY PATTERN OF PASSENGER CARS AND TRUCKS EXPRESSED AS PERCENT OF AVERAGE HOUR OF DAY (WEEK-DAY 1955) OMAHA TRAFFIC STUDIES WILBUR SMITH 8 ASSOCIATES Street capacity in urban areas is severely restricted due to the conflicting demands of cross-street traffic, use of streets by standing and parked cars, blocking of intersections by crossing pedestrians and turning vehicles, and other non-traffic uses of the streets. The Highway Research Board's Capacity Manual sets tent ative capacity standards for urban streets which have been applied to some of Omaha's principal traffic arteries. Traffic demands which exceed optimum street capacity lead immediately to congestion and delay. The most restrictive location along a street very often estab- lishes street capacity over a considerable length of the thoroughfare. Traffic sign als frequently mark points of limited capacity where heavy cross-traffic requires an alternate sh aring of the inter section by vehicles operated on each of the intersecting streets. A variety of traffic engineering techniques have been developed which min- imize the negative effects of traffic signals and other capacity restrictions. Within the past several years many of these remedial me a sures have been effected on Omaha's most important streets. Most of these are arterial streets which radiate from or pass through the Central Business District. A one-way street system shown in Figure 7 has served the Central Business District for several years, with a number of radial streets restricted to one-way opera- tion for some distance out from the downtown area. In creased street efficiency has been achieved by eliminating turning conflicts at intersections and by timing signals for continuous progressive traffic flow along the length of each street. Signals have also been re-timed to favor major traffic flows. Downtown streef efficiency has also been increased by replacing street cars with busses, by extending curb loading zones, and by providing more off-street parking sp ace. Most of Omaha's downtown streets have a povement width of 60 feet, providing for four lanes of moving traffic and two lanes for parking. Such streets should accom- modate about 600 vehicles per lane per hour, according to capacity ratings. The Peak- hour for traffic in the business area occurs between 5:00 and 6:00 P.M.; creating a traffic demand equal to 11.8 per cent of the 24-hour flow. The heaviest 24-hour volume (19,302 vehicles) is recorded on Douglas Street east of Ninth Street, creating a peak-hour volume of 1,548 vehicles which measures well under the capacity for this street. Yet this - 24 - section of Douglas Street, as well as nearby intersecting streets, is daily congested during the evening peak-hour period, due principally to the deficient capacity of the Ak-sar-ben Bridge and its approaches. Regulations and Controls – Traffic control signals have been installed at many intersections in Omaha. Signa iized inier sections are depicted on the map, Figure 10. Four major interconnected signal systems, each with a master controller, help to expedite the flow of traffic. The most extensive of these systems covers the downtown business district, and extends from Thirteenth Street on the east to Twentieth Street on the west, except that on Douglas Street the interconnected system runs to Ninth Street, and from Chicago and Davenport Streets on the north to Jacks on Street and St. Mary's Avenue on the south; also on South Sixteenth Street, the system is extended one addi- tional block to Leavenworth Street. A second system of interconnected traffic signals extends a long Cuming Street from Sixteenth Street to Thirtieth Street and Burt Street from Twenty-seventh Street to Sixteenth Street. A lengthy section of Dodge Street is controlled by interconnected signals which extend from Park Avenue and Thirtieth Street west to Sixtieth Street. The fourth major signal system embraces several blocks in South Omaha -- Twenty-fifth Street from “L” Street to ‘‘N’’ Street; Twenty-fourth Street from “L’’ Street to “O’’ Street, and “L” Street from Twenty-third Street to Twenty-fifth Street. Two pairs of interconnected signals are operated on “Q’’ Street, one tying in the Twenty-seventh Street intersection with that at Twenty-eighth Street and the other tying in Twenty-fourth and Twenty-fifth Streets. Practically all of Omaha's signals operate on a 60-second cycle. Average Travel Time — Figures l l and 12 show the peak and off-peak speed characteristics of travel on principal arterial streets in Omaha, as measured from the Central Business District. The data plotted here have been averaged from a number of - 25 - -------- ------- suffs º - Figure 10 TRAFFIC SIGNAL LOCATIONS 1955 OMAHA TRAFFIC STUDIES - O 2 3. SCALE IN MILES WILBUR SMITH 8 ASSOCIATES speed runs on each street, made during conditions of representative traffic flow. Average speeds on arterial streefs increase gradually as distance from the Central Business District increases. Peak hour travel is somewhat delayed by excessive traffic demands. Traffic signals are the most important single source of delay since they allow only part-time access to signalized intersections from each street thus **ntrolled. Over-all trip speed between external cordon and Central Business District * - - - - ... . . . | a T ſy I º º -T-I 1 . . " - - - ! . : - - -- f º - I -1 - 1 - . . Civ e ſ C1 ge's d b ou i i ö III PI 1. O I I III O S i r ouie S. ſhe se p speed S in C iude s iopped de i ay regardless of cause. Speed and Delay — Figure 13 graphically illustrates the results of speed-delay "ns on four of Omaha's major arterials between the intersection at Fifteen th and Jackson Streets and the centroids of four outlying zones. Traffic Accidents – The accident spot map shown in Figure 14 is mute evidence of the traffic congestion and vehicular conflict which exists on heavily traveled streets, particularly at important intersections. This pattern of accident distribution is typical of every large American city. The most heavily traveled streets are indicated by the heavy bands of accident markers, clustered densely about each major intersec- tion. Traffic accidents portrayed this way are but a secondary measure of excessive traffic demands on an out-of-date street grid unsuited for the mass movement of modern automobiles. According to the 1955 records of the Traffic Division of the Omaha Police Department, 2,086 accidents were reported to have occurred at 257 intersections through- out the city. A review of this record shows that Dodge Street had the worst accident history in the city, leading all other streets with 286 accidents in the distance from Twelfth Street to Seventy-second Street. The worst inter section in the city was at Dodge and Forty-second Streets with a record of 27 accidents. Other hazardous thoroughfares were Douglas Street, with 160 accidents, and Leavenworth Street, with a history of 15l accidents. The Ak-sar-ben Bridge accounted for 21 accidents. Street Sufficiency in Central Business District – Some 95,000 passenger cars and 18,500 trucks move in and out of the Central Business District on an average week- ſ day. Nearly 56 per cent of these trips begin or end in downtown Omaha, while the - 27 - - S- almºnt - |L ELLFFs º, LEGEND º 4-5 TRAVEL TIME Figure 11 PEAK HOUR PASSENGER CAR TRAVEL TIME IN MINUTES BETWEEN CBD AND ZONE CENTROIDS (WEEKDAY-1955) OMAHA TRAFFIC STUDIES O I 2 3. SCALE IN MILES WILBUR SMITH 8 ASSOCIATES Figure 12 OFF-PEAK PASSENGER CAR TRAVEL TIME IN MINUTES BETWEEN CBD AND zonE CENTROIDS (weekDAY-1955) OMAHA TRAFFIC STUDIES - - O 2 3. SCALE IN MILES - S- -------- LEGEND 4-5 TRAVEL TIME ſº Minutes * wil-BUR SMITH 8 ASSOCIATES - S. GMAL DELAY - TURNING DELAY - TRAIN DELAY - OTHER DELAY - FREE FLOW º SLS HI OEI ON V NOS XOV T^ w/A → N 1，1 ‘OO ！!！!！!S O IL NOS XOV^ ON v Hl. Gl -|- | QAmº 30 N280-13 QNºv H1 61 '30000 º H1 gi w 1^ B 00188 NOW HOW OIL NOSX10 v ſº C1 NV7 HI GI SILBERH1S Ww NÅ!！! 0 N （ H L C I VIA W （N） \！! 0 N \， AAOTTO H Addw H O 1 NOS×Own O'Nv H1 gli S 1338 LS 39.000 QEN （ H L G | w | A 39000' 0 N \， 0 N 2.， O 1 NOSX Oſ ſº ONV H I GI (SEI， NIW © NI ) ：： I - O H-19 NE|| || ſae | || |- |- |- O [− |- | © |- |- (） |- […] L Figure 13 SPEED-DELAY RUNS ON FOUR MAJOR ARTERIALS (Peak-Hour) OMAHA TRAFFIC STUDIES WILBUR SMITH 8 ASSOCIATES - Sº ----- ------ ------ - - - - º ºs - Figure 14 LOCATION AND NUMBER OF VEHICLE ACCIDENTS 1955 OMAHA TRAFFIC STUDIES • Vehicle Accident x Multiple Vehicle Accidents ------ - -------- O 2 3. SCALE IN MILES WILBUR SMITH 8 ASSOCIATES remainder represent trips which are just passing through and have neither orgin or destination in the district. Most streets in downtown Omah a have a paved width of 60 feet between curbs, with metered parking permitted on both sides. One-way traffic regulations are in effect on m any streets, with traffic flow supervised by a modern system of traffic signal controls. The principal streets radial to the Central Business District accommodate nearly 70,000 vehicles each day, and remaining traffic utilizes the more localized thoroughfares. These principal streets are Lodge, Farn am, Douglas, Harney, St. Mary s and Leavenworth on the west, Dodge, Farn am, Douglas, Jackson and Harney on the east, Sixteenth, Nineteenth and Twentieth on the north and Thirteenth and Twentieth on the south. Combined capacity of these facilities is approximately half of the to fal cordon cap a city, or enough to accommodate about 135,000 vehicles per day, assuming the present hourly distribution of traffic and also anticipating a reasonable facility of movement within the business district. Existing traffic demands are well with in street cap a cities and addition al traffic growth expected over the next 15 to 20 years can be absorbed by downtown streets provided street operations are kept efficient, and parking requirements are met. The most serious problem of traffic operations in downtown Omaha occurs on the approaches to the Ak-Sar-ben Bridge, due both to limited bridge capacity and to restrictive traffic and operational controls on the approaches. Most other operational difficulties which occur in downtown Omaha result from parking movements, restrictive signal timing, truck loading, and similar traffic conflicts. Substantial street capacity increases can be achieved by elimination of peak-hour curb parking and improved connectors and routings on the Bridge approaches. While the traffic congestions which occur on the downtown streets create confusion and delay, very few of them are of a sustained nature. Conventional traffic engineering treatments should relieve most types of traffic problems as they occur, although signal delays, pedestrian, influences, etc. are - 32 - common problems inherent to downtown traffic operations because of the lack of special- ization of streets and terminals. They require constant expert attention to assure maximum street efficiency. Major Traffic Generators The Omaha origin-destination survey found that 402,868 internal vehicle trips were made during a typical 24-hour weekday in the fall of 1955. Traffic data were col- lected during the months of October and November, which are average traffic months largely unaffected by peak summer vacation travel or by relatively low winter-fime volumes. Continuous traffic volume records made on the Ak-sar-ben Bridge attest to the representative character of the period during which trip data were gathered. The Omaha trip reports may therefore be used as a reasonable measure of average annual daily travel for the year 1955. The Central Business District – 1944 and 1955 – The area identified as Central Business District in the 1944 study (tract l 18) is identical with the Central Business District designation defined in the 1955 survey (Zone 00). Some very interest- ing comparisons can be developed as shown in Table 7. Most surprising is the apparent decrease in travel generated in the CBD. Perhaps the war-time worker population was greater in downtown Omaha in 1944 than in the fall of 1955. Interview sampling error may also account for some of the discrep- ancy. In any event, it is not very likely that travel to the CBD has actually experienced the amount of decrease shown. The area is expected to induce a continually increasing volume of travel in future years, although future trip growth will be at a much lower rate in the CBD than in the Metropolitan Area as a whole. Most new population increases are taking place in areas peripheral to the presently urbanized portions of Metropolitan Omaha. In 1955 the Central Business District was the focal point of 117,700 trips taken on all modes of travel by people living both within the area and outside of it. In 1944 the Central Business District generated a total of 127,400 trips both from within and without the Metropolitan Area. In 1955 some 88,600 trips, or about 75 per cent of the total, were drivers and passengers in 66,700 autos, trucks, and taxis. In 1944 the comparable volume of traffic amounted to 55,400 persons, who entered the area in 38,000 - 33 - Table 7 Omaha Traffic Studies TRIPS TO AND FROM CENTRAL BUSINESS DISTRICT 1944 1955 All trips to, from, within Central Business District' 127,387 117,653 All auto, truck, taxi trips 38,0ll 66,779 All internal trips - all modes 124, 227 109,760 Auto and taxi driver trips 32,233 50,519 Truck driver trips 2,618 8,367 Auto, truck, taxi passenger trips 17,414 21,826 Transit rider trips 71,962 29,048 External trips” 3, 160 7,893 Auto driver trips 2,807 7,090 Truck driver trips 35l 803 1. Zone 00 in the 1955 study coincides with tract 1 18 in the 1944 study 2. External trips include travel between the CBD and Council Bluffs - 34 - vehicles. These accounted for 43.5 per cent of all persons traveling to and from the Central Business District. The Central Business District was the focus for approx- imately 3,000 truck trips in 1944. In 1955 the Central Business District accounted for 9,200 truck trips. - The most outstanding change in Central Business District travel habits since 1944 has been the very marked decline in transit use. In 1944, transit travel to the Central Business District amounted to 72,000 trips. In 1955 only 29,000 trips, or 40 per cent of the 1944 volume, were made to and from the Central Business District by transit each day. Private automobile trips generated by the downtown area have increased by 65 per cent in the same period of time. The trips generated each day in the Central Business District account for 17 per cent of all trips performed in cars and transit vehicles in the Omaha study area. They account for 15 per cent of the auto driver trips made by residents of the area; 15 per cent of the auto passengers; 35.5 per cent of the transit riders; le per cent of the cars which cross the external cordon line with infernal origin or destination; 11.5 per cent of the truck trips made entirely with in the city; and 8 per cent of all trucks crossing the cordon line with internal origin or destination. The figures for external trips are distorted, of course, by excluding from the study area the city of Council Bluffs and adjacent urbanization in lowa. Almost half the external Central Business District trips are generated across the Ak-sar-ben Bridge, and a large proportion of this trave i should be considered local in character. Secondary Business D is frict – The secondary business district, Zone 01, ranks next to the Central Business District in importance as a traffic generator. About 24,500 vehicular trips per day were generated between this zone and other areas with in the city (approximately 6 per cent of a || internal driver trips). Nearly a third of these (7,900) were truck trips. An additional 3,350 trips were generated between the area and the external cordon, about 1,000 of them made by trucks. Stockyards — A third large traffic generator was the Union Stockyards in South Omaha (Zone 83). This zone generated 10, 157 internal passenger car trips, including taxi trips, and 824 internal truck trips. Trips between this zone and external are as consisted of 81 l passenger cars and 1,035 trucks. Of these, 73 l were stock – 35 - trucks, 30 per cent of which were tractor semi-trailer combinations. The South Omaha Bridge (Station 24) contributed about 30 per cent of this external travel. Offutt Air Force Base – Personnel of and visitors to the Strategic Air Com- mand Headquarters, Offutt Air Force Base, located south of Omaha, accounted for 6,292 daily internal vehicle trips. Nearly one-half of these trips were between the Base and Bellevue, located immediately east of the Base. Of the total of 6,292 internal vehicle trips, 6, 118 trips were made by passenger cars and 174 were truck trips. External trips to and from the base totaled 1,429 passenger cars and 222 trucks. Others — Allied closely to the Stockyards district is Zone 84, immediately adjacent to and south of Zone 83. Zone 84 is largely residential, but several of the meat packing and processing plants are also located there, and the zone generated a considerable amount of vehicular traffic. Internal passenger car and taxi trips to and from the zone totaled 15,822 and truck trips, 2,716. Travel between the zone and external areas amounted to 864 passenger car trips and 198 truck trips. Here again, the South Omaha Bridge was the most important source of external trips. - 36 - PART || THE ORIGIN-DESTINATION SURVEY An origin-destination survey provides information on all facets of Urban travel except for trips that are made on foot. Travel can be related directly to places of residence and employment, to purpose of trip, to hour of travel and mode of transporta- tion employed. The origin-destination data have many uses. Planning agencies can use trip information to gain a better understanding of the way the city functions and to help establish the location and design criteria for new traffic facilities. Trans it companies can put the data directly to work in developing more efficient schedules and anticipating route changes. Business men probe trip origins and destinations to discover the market area served by retail districts. Sociologists explore them for patterns of Urban behavior. The sponsors of the Omaha Study have sought this information for use in locating needed trafficways. When the 1955 pattern of urban travel has been properly and lyzed, evaluated and projected, a system of arterial streets and express highways can be laid out to properly serve the Omaha region. By projecting traffic data to fit land Uses anticipated for 15 years hence, the volume of traffic demands on this network of highways can be anticipated over a substantial portion of its functional life. Initial design of each segment of roadway can thereby be controlled to avoid pre mature obsoles- C en Ce . The Dwelling Un if Sample – The conventional home interview origin- destination survey is made by questioning a representative “sample” of the Urban population. A carefully selected sample of dwelling units within the study area is designated for interview, the number of units being based on the proportion of the populace that the sample is designed to include. Trained interviewers call at each of the sample dwellings and question all residents concerning all of the travel performed by - 37 - º Figure 15 MAP OF METROPOLITAN OMAHA sHow ING TRAFFIC survey tracts, zones & External STATIONS 1955 OMAHA TRAFFIC STUDIES --- O 2 3. SCALE IN MILES --- -------- WILBUR SMITH 8 ASSOCATES them on a specific day. The completed interviews are then expanded to represent travel performed by the total number of persons known to be living in the survey area. A seven per cent sample was selected for study in Omaha, since a sample of such size can be depended upon to yield adequate information for the evaluation of major traffic movements in metropolitan areas of that population group. A further discussion of sample adequacy is presented in Appendix E. Truck and Taxi Samples – The sample of commercial vehicles constituted 17 per cent of the trucks registered in the Omaha study area and 100 per cent of the taxis. It is probably impossible to obtain a complete listing of all trucks used in and around Omaha since some are not registered locally, but a list of those registered in the are a was obtained. A complete taxi list was also secured and trip reports obtained from the driver of every vehicle. Every “6th” vehicle was selected from the truck list by license number and the owner or driver was interviewed. Truck and taxi fleet operators were generally cooperative. Most of the deficiency in truck trip reports is the fault of an incomplete sample. Some locally registered vehicles cannot be located; some vehicles in the ared are not listed; and vehicles intercepted at the cordon are frequently responsible for several internal trips although only one or two trips will be recorded when drivers are interviewed. Roads ide Interview Sample – The interviewed sample of traffic at the cordon line is usually a much larger proportion of the external traffic Universe than is obtained of the internal traffic in the home interview. Cordon interviewing is easy and rapid, and the proportion of traffic interviewed is known precisely. It is not uncommon for inter- views to equal 50 per cent or more of the external trips on the day of the survey. The reliability of expanded external trips is therefore greater than that of internal trips, but the volume of such travel is usually a small fraction of the total volume of travel in the O re C. . - 39 - 7~. --- --------- 559 --------- --- Tºlº – OMAHA METROPOLITAN º º 4. -------- O5 AREA Gºº 572 679 * 07 ------- --- | sºn-Gº-L-L-L Figure 16 ZONE MAP DOUGLAS AND SARPY COUNTIES NEBRASKA OMAHA TRAFFIC STUDIES -------- O 2 3 4 5 5 SCALE IN MILES WIL BUR SMITH 8 ASSOCIATES 705 -- \\ . - 707 71.4 --- --- *D --- 24. - Dºlºe- *D --- - 25 28 7-O--> 708 - 7 1- |23 --- ſº -------- º T- -------- ºD ºr ºs-Tºº cle - *O- 7 O2 - 7-12 º |- 702 26 - ----- ------ ------- - - - - 27 7-O- 710 * || º [lºn - -Dºo- º |2| --- --- *T -------- Figure 17 ZONE MAP POTTAWATTAMIE COUNTY TOWA OMAHA TRAFFIC STUDIES --- O seaſe º º G WILBUR SMITH 8 ASSOCIATES Methods and Coverage of the 1955 Study – The study area for the 1955 origin- destination survey incorporated most of the heavily populated portions of Douglas and Sarpy Counties. All trip data for the 1955 study were coded to census tracts within the city of Omaha. Outside the city, but within the limits of the study area, arbitrary sub- divisions were made and new tract numbers assigned. Since the 1944 survey had been handled in similar fashion, data are largely comparable except in peripheral areas where cordon limits were extended for the 1955 study. Figure 15 defines the limits of the present survey. - 41– In the 1955 study, census tracts have been combined to form a series of tº º 2 3 S - - : e - - - º t Z O In 6 S . uch zoning has reduced the number of subdivisions within the survey ared and, by combining trips generated in two or more tracts, has increased the size and stability of the average inter-zonal movements. The Omaha study area has fit us been reorganized into 62 zones for which trip data have been tabulated in Appendices, Cl, C2, C3 and D. In the 1944 study, the counties adjacent to the Omaha Metropolitan Area were subdivided info small tracts which bear no relation to political boundaries within the counties. This system of tracts forms the external subdivisions of area in the 1955 study as shown in Figures 16 and 17. External tracts have also been combined into t ‘zones” which form the basis for trip analyses in this study. At the tract level the 1955 data are comparable to 1944 data. All phases of the 1955 internal survey were carried out by the consultant. The survey methods employed were basically those prescribed by the United States Bureau of Public Roads in its ‘‘Manual of Procedures for Home Interview Traffic Study'', revised edition, October, 1954. Questions of interpretation were resolved by conferences between representatives of the consultant, the Nebraska Department of Roads and Irrigation, and the United States Bureau of Public Roads. Data collected in the internal studies are representative of a typical autumn weekday in 1955. Much of the external cordon survey — the roadside interview phase of the study — was conducted by the Program and Planning Section of the Nebraska Department of Roads and Irrigation. The consultant made roadside interviews at only three stations in Nebraska, but was responsible for interviewing traffic on all of the four Missouri River Bridges. All external trip data were adjusted to traffic volumes representative of a typical autumn weekday in 1955. The Home Interview Survey — A seven per cent sample of dwelling Units within the study area was selected. Interviewers visited each sample dwelling and recorded all of the trips performed by each member of the family on the day preceding the interview. - 42 - Dwelling units were carefully pre-selected to insure an accurate cross section of Omaha's population. In most parts of Omaha the selection was made from San born maps. In areas not covered by the maps, the sample was selected in the field. In addition to trip data, interviewers also obtained information concerning the number of people living in each dwelling and the number of cars they owned. These data can be related to population censuses and car ownership records, which greatly extends the usefulness of the trip data. The dwelling unit data, when expanded, contain an estimate of the population residing in each census tract. The se estimates were compared with the special popula- tion estimates prepared by the Omaha Planning Office for 1953 and the regular cens uses of 1950 and 1940. The home interview sample was found to be less than intended in some of the very populous tracts in central Omaha due primarily to deficient recording of dwelling units on the maps used for sample selection. All such tracts were carefully reviewed and adjustments made for under-sampled tracts which have had no major change in population status since the 1950 census. The Truck Survey — The 1955 truck registration lists were carefully examined and a 17 per cent sample of trucks registered in Omaha was selected for study. The owner's address was obtained for every sixth truck registered in the Omaha study area, and the driver interviewed to determine the origin and destination of trips performed by each truck on a specific weekday. Sample data were then expanded to represent the travel performed by all trucks registered in Omaha. The Taxi Survey — The procedures described for the truck survey were followed in making the taxi study. Cooperation of the taxi companies was enlisted, and the cab drivers' manifests were recorded for all trips made on an average autumn weekday. The External Survey — Information on travel to and from Survey Area can be obtained by stopping traffic at external cordon stations and interviewing drivers. If an accurate count is made on all roads crossing the cordon, the roadside interviews can be - 43 - --L---> Figure 18 SCREEN LINES 1955 --- OMAHA TRAFFIC STUDIES - . - - O 2 > SCALE IN MILES wil-BUR SMITH & Associates \ GROUND COUNTS O-D VOLUMES TEXTERNAL Figure 19 COMBINED NORTH AND SOUTH SCREEN LINES PASSENGER CARS OMAHA TRAFFIC STUDIES wilBUR switH a Associates adjusted to represent average daily traffic to, from and through the city. In the 1955 study the external sample interviews amounted to 64 per cent of the daily volume of traffic at the cordon. Data Obtained The studies described above resulted in the collection of the gross volume of trip data listed in Table 8. - 45- Table 8 Omaha Traffic Studies TRIP REPORTS OBTA|NED FROM INTERVIEWS Size of Sample Trips Tofa | Trips' Study Percent from Interview (Sample expanded) Home interview 7 31,049 550,3872 Truck interview 17 9,34] 71,924.2 Taxi interview 100 6,085 6,085 External Cordon 64 39,052 60,853 Total trips 689,249 ! Note – Expanded data represent average autumn weekday. Note – Internal trips contain an adjustment for unreported travel. Reliability of Dafa – Vehicle Trips External trip interviews are easily related to the known volume of traffic passing through each interview station. The samples obtained were a large proportion of total traffic and data have been adjusted to average daily values with much confidence in the accuracy of results. Internal survey data are more difficult to evaluate. The sample is smaller and there, is no sure way of defecting unreported trips. To estimate the reliability of in fernal data, east-west “screen lines’’ shown in Figure 18 were established in the northern and southern parts of the survey area, each located along a railroad line crossed by relatively few streets. Traffic ‘‘ground counts’’ were made on each street crossing the screen lines, classified by type of vehicle passing in each direction and by hours of the day. - 46 - Interviews were expanded by hours and purpose of trip, for each type of vehicle, and all trips crossing each screen line were identified. Trips from the external interviews were assumed to be correctly represented at the screen line. These trips were subtracted from the ground count made at the screen line so that the volume of trips which should be identified in the internal trip reports (home interviews and truck and taxi interviews) could be determined. Peak-hour travel, which includes the work trips, was found to be very well re- ported. Off-peak travel, not so completely reported, was subject to special adjustments to bring trip interview data within 90 per cent of ground counts at the screen lines. The screen line check is illustrated in Figure 19 and Appendix A-l. Auto and Transit Passengers — Screen line counts can be directly related to automobile and truck trips, but do not measure trips made by auto passengers or frans it riders. It is usually assumed that auto passenger trips are under-reported to the same degree as auto drivers. This assumption has been made, applying adjustments to duto passenger trips. Trans it rider trips reported in the origin-destination survey can be compared directly to the daily volume of transit use as reported by the Omaha Transit Company. Weekday travel during the months of October and November when the Survey was in progress produced 65,985 adult fares each day and 10,880 student fares. Transit trips made on passes would add to these, so that total daily trans if rider volumes averaged approximately 77,400 trips. Transit trips as reported and expanded amounted to 68,000 or 90 per cent of the volume actually known to take place. In the an alysis of future trip potentials, if is desirable that the data used be expanded to represent the known volume of travel. This adjustment has been made by increasing transit trips to work by a factor of 1.05 and by applying an adjustment factor of 1.20 to the non-work trips. The adjusted trip volume of 78,233 trips is slightly larger than the daily volume reported by Omaha Transit Company - 47 - - - sous-ºver TRAFFIC sººn º -º-º-º: uwes Essº nº shown Figure 20 PRESENT DESIRE LINES OF INTERNAL TRAVEL EXCLUSIVE OF CENTRAL BUSINESS DISTRICT OMAHA TRAFFIC STUDIES O 2 3. SCALE IN MILES WILEUR SMITH 8 ASSOCATES Trip Desires in Omaha Metropolitan Area Adjusted trip data for each mode of travel have been summarized in Appen- dices C-1, C-2, C-3 and D and the most significant movements have been plotted as ( & te * desire lines of travel” between zone centroids, as follows: figure 20 illustrates the relative volumes of inter-zonal travel for all vehicle movements taking place in the Omaha study area with the exception of trips generated to and from the Central Business District (Zone 00). The following volumes of non-Central Business District vehicle trips were found to originate and end within the Omaha study area on an average weekday in 1955: Auto Drivers 277, 129 Taxi Drivers 3,226 Truck Drivers 63,627 All Internal Vehicle Trips (non-Central Business District) 343,982 The exhibit depicts all zone movements amounting to 60 or more trips per day. Figure 21 shows the origins of all internal vehicle trips, with origins or desti- nations in the Central Business District. The following trips had a terminus in that Cire C. : Auto Drivers — 47,660 Taxi Drivers – 2,859 Truck Drivers — 8,367 All Driver Trips 58,886 All zone or station volumes exceeding 60 trips per day are shown on the exhibit. Figure 22 shows the internal origins and destinations of all vehicle trips crossing the external cordon on an average weekday. Zones of important generation - 49 - - - - -- - - - - º -------- - - - - H TRAFFIC s Le soon – aboo- - º º - averº 24 Hous wºrkpº - º _- hºtº ºves º Tº so Nºt ºwn Figure 21 PRESENT DESIRE LINES OF INTERNAL VEHICULAR TRAFFIC To CENTRAL BUSINESS DISTRICT OMAHA TRAFFIC STUDIES º - – O 2 3. SCALE IN MILES WILBUR SMITH 8 ASSOCIATES ºver Mesoº |4 -------L--> - LEG--- ------ extenºa. vºlu- - - - - - - FFIC scºut ºl- --- - - - --- \ zºº- ------ º º weeknº - Nºte volumes LEss than so T ----- – º D Figure 22 PRESENT DESIRE LINES OF EXTERNAL-INTERNAL TRAVEL OMAHA TRAFFIC STUDIES ſ. 5 - -. --- - O 2 3. SCALE IN MILES º WILBUR SMITH 8 ASSOCIATES are the Central Business District and the principal industrial areas in the central part of the city. The following external trips were generated on an average 1955 weekday: Auto Drivers — Auto Drivers — Truck Drivers — Truck Drivers — All External – to and from Central Business District 7,090 non-Central Business District 38,069 to and from Central Business District 803 non-Central Business District 9,025 Internal Drivers 54,977 Movements of more than 60 trips per day are shown on the exhibit. Figure 23 shows the pattern of through movements between cordon stations. The most significant movement is that between Stations 23 (Ak-sar-ben Bridge) and 35 (U.S. Route 6 and U.S. Route 30-A west of Omaha). This movement amounted to 1,76 l cars and 31 l trucks on the average 1955 weekday. Other significant movements are those which parallel the Missouri River through Stations 21 (U.S. Route 73) and 23 (the Ak-sar-ben Bridge) and between Station 26 (U. S. Route 73 and U. S. Route 75) and Station 23 (the Ak-sar-ben Bridge) and 24 (South Omaha Bridge). Total movements of trips through the Omaha survey area were as follows: Auto Driver Trips 4,858 Truck Driver Trips 1,008 Total Through Drivers 5,866 Movements exceeding 60 trips per day are shown on the figure. Band width is proport- ional to volume of movements. Figure 24 shows the movement of passenger car drivers generated in the Central Business District. Data are shown for both internal and external movements. The Central Business District generated a total of 57,609 auto driver trips on an average 1955 weekday. This volume is made up as follows: Auto Drivers — Infernal 47,660 Auto Drivers — External 7,090 Taxi Drivers – Internal 2,859 All Auto and Taxi Drivers 57,609 Auto and taxi driver movements in excess of 60 trips are shown graphically in Figure 24. - 52 - Figure 23 PRESENT DESIRE LINES OF THROUGH EXTERNAL TRAVEL OMAHA TRAFFIC STUDIES -- O 2 3. SCALE IN MILES --sºus-ºves --- LEGEND -- --- * º tº wº WILBUR SMITH 8 ASSOCIATES Figure24 PRESENT DESIRE LINES OF PASSENGER CAR DRIVER TRIPS TO AND FROM CENTRAL BUSINESS DISTRICT OMAHA TRAFFIC STUDIES O | 2 3. SCALE IN MILES wesous-ºver 4. -Lurºs - TRAFFIC Cº- º --- ----- º tº so --- WILBUR SMITH 8 ASSOCIATES A record is also available for internal auto and taxi passenger trips, which follow the same desire pattern as that developed for drivers. The following internal Passenger trips were generated in the Central Business District on an average 1955 weekday: Auto Passengers 19,673 Taxi Passengers 1,962 All Auto and Taxi Passengers 21,635 Taxi passengers are not well reported, since data on their travel must come from the home interviews. Many taxi trips are made by persons who are temporarily in the city for business or other reasons. No charf has been prepared for auto and taxi passengers generated in the Central Business D is frict. Figure 25 presents a graphic description of non-Central Business District travel by passenger car s and taxis. Trips in this category amounted to 318,424 move- ments per day at the time of the survey. They were composed as follows: Auto Drivers – Internal 277, 129 Auto Drivers — External 38,069 Taxi Drivers – Internal 3,226 All non-Central Business District Auto and Taxi Drivers 318,424 Trips in volumes of 60 or more between zones or between stations and zones have been sh own in the exhibit. Auto and taxi passenger data were also collected in the internal phases of the No drawing has been prepared to illustrate passenger trips The following origin-destination study. since their pattern of movement is almost identical to that of drivers. volumes of non-Central Business District passenger trips were found to be made in the study area on each 1955 weekday: Auto Passengers – Internal 123,250 Taxi Passengers – Internal 3,342 126,592 Total Internal Passengers - 55 - wesous-ºves -- - º . council autºs - TRAFFIC --- -º- -º-º-º: ---- ºss º - sººn º Figure 25 – PRESENT DESIRE LINES PASSENGER CAR DRIVERS - - EXCLUSIVE OF CENTRAL BUSINESS DISTRICT OMAHA TRAFFIC STUDIES O 2 3. SCALE IN MILES WILBUR SMITH 8 ASSOCATES Figure 26 shows the pattern of transit rider trips to and from the Central Business District. Note that the most substantial volumes of travel are generated to the Central Business District from nearby zones of heavy population concentration. Zones at the periphery of the city generate few, if any, Central Business District transit trips because (1) transit service is infrequent to sparsely settled areas and (2) demand for transit service is low in zones of high car ownership. The volume of transit trips generated in the Central Business District on an average 1955 weekday amounted to 29,048 movements. Figure 27 illustrates the pattern of non-Central Business District transit travel in Omaha. Non-Central Business District trips accounted for only 63 per cent of transit use on the average 1955 weekday. The remaining 37 per cent were generated by the Central Business District. Non-Central Business District trips totaled 49, 185, of which all inter-zonal movements in excess of 60 trips are shown graphically in this exhibit. Transit use is heavily concentrated toward the center of Omaha. This is to be expected, since all major fransit lines are oriented radially from the Central Business District. Principal generators in central Omaha, outside the Central Business District, are the industrial zones. This is not surprising since more than half of all transit trips are made by persons going to work or returning home from work (see Appendix B-2 Part 3). Figure 28 depicts the trip desires of all truck travel in the Omah a survey are a. Truck trips in the area total 82,760, as follows: Central Business District Truck Trips – Internal 8,297 Central Business District Truck Trip s – External 803 Non-Central Business District Truck Trips – Internal 63,627 Non-Central Business District Truck Trips – External 9,025 Through Truck Trip s 1,008 All Truck Trips 82,760 Volumes of commercial travel, in excess of 60 trips per day between generators are shown on the exhibit. - 57 - TRAFFIC --~~ º º 24 Hous weekbºx - Less tº so. Figure 26 PRESENT DESIRE LINES TRANSIT RIDERS TO AND FROM CENTRAL BUSINESS DISTRICT OMAHA TRAFFIC STUDIES - —i. J 2 3. SCALE IN MILES WILBUR SMITH 8 ASSOCIATES wesous-ºves 4. - - - - - -Luº TRAFFIC S º º 2-no 24 Hour Figure 27 PRESENT DESIRE LINES TRANSIT RIDERS EXCLUSIVE OF CENTRAL BUSINESS DISTRICT OMAHA TRAFFIC STUDIES I O 2 3. SCALE IN MILES WILBUR SMITH 8 ASSOCIATES wesous-ºver |4 TRAFFIC --~~ --~~ 2000 24 Hour weeknº **** shown - --- Figure 28 - - PRESENT DESIRE LINES ALL TRUCK DRIVER TRIPs OMAHA TRAFFIC STUDIES O 2 3. SCALE IN MILES WILEUR SMITH 8 ASSOCIATES PART IV CHARACTERISTICS OF TRAVEL IN THE METROPOLITAN AREA The pattern of trip origins and destinations shown in Part | || portrays average daily travel behavior in the fall of 1955. But, like the city if self, travel patterns are dynamic; already the 1955 study is becoming out of date. Within a decade these data may be as obsolete as the 1944 survey is today. This does not mean that a new survey ought to be made every year in order to mainfa in an up-to-date record of travel habits. It means, though, that the forces which motivate travel ought to be measured and understood so that travel patterns can be anticipated. Fortunately, the origin-destination survey contains information from which these measures may be derived. Trips are made by people who travel about in pursuit of their daily affairs. Nearly every household contains one or more persons who work away from home. Others go to school, or go shopping or make business trips; some make trips to playgrounds, to a show, or go out to dinner. Whether these trips will be made by car or bus may depend on the ability of each household to maintain a car – or perhaps two or more cars. Length of trip and accessibility by bus may help determine which trips are made by car and which by transit. To some degree, each trip is determined by circumstances such as the se. It is reasonable to expect that the influence of some of the more impelling factors can be detected in the trip reports from the origin-destination survey. In deriving characteristics of Urban travel, it is important to relate trips to variables which can be measured or predicted with considerable confidence. The immediate uses to which derived data are to be put should also be fully considered. The Shape of the Future City In the case of the Omaha study, estimates of travel in the Metropolitan Area are to be projected some 15 years into the future to provide information upon which to base the design of new highways. - 6 1 - Some a spects of future Omaha can be predicted with considerable confidence. If the area is expected to contain a population of 430,000 people by 1975, as estimated by the Mayor's Planning and Development Committee in its report of November, 1955'., then a logical pattern of residential distribution can be developed for a population of that “annualar ring'' type, much size. Historically, Omaha has grown by increments of an like a free adds to its diameter. That process can be expected to continue, modified by other factors such as trends toward larger residential lots in new suburbs. An estimate of this type applies to an estimate of total population, not a particular year, and should be used as such. If growth turns out to be slower or more rapid than had been antic- ipated, traffic demands related to a given population can still be evaluated in terms of the proportionate population increase which may have occurred. |-abor Force in Metropolitan Area – The number of persons in the labor force in each tract of the Omaha area is shown in fabulations of the 1950 census data as published by the Bureau of the Census *. These figures were out-of-date at the time of the origin-destination survey, of course, but the proportion of labor force to population in each fract can be expected to remain substantially the same from census to census in the more stable fracts, and can be anticipated with reasonable accuracy for expanding populations at the periphery of urbanization. The home-interview survey has produced a 1955 census of population for each tract, so that an accurate estimate of labor force in the area can be prepared for use in the se analyses as shown in Appendix F. The proportion of the urban populace which makes up the future labor force can be estimated, based on population distribution. The labor force is the source of all employment in the community. Employment in Each Zone – At the time that field data were collected for the home-interview survey, no reliable estimate of employment distribution could be found. It was reasoned, however, that a logical picture of zone employment could be derived by summarizing all trips to work from home for each zone. The resulting pattern of use “E stimates of Growth and Development: Omaha and Environs'', mimeographed bulletin, Mayor's Planning and Development Committee, 1955. 2 1950 U. S. Census of Population, Omaha, Nebraska, Table 2, Published by U.S. Department of Commerce, Bureau of the Census. - 62 - represented only those persons who arrive at work by car or bus. It was then reasoned that no great discrepancy would develop if the remaining employed population were distributed by applying a uniform expansion factor to employees who arrived in each zone by car or transit. Most zones of heavy employment are located near populations which are within walking distance. The resulting estimate of zone employment is shown in Appendix F. Location of future employment is also predictable, although less so than population and labor force distribution. An ‘‘industrial revolution'' is presently taking place and its future implications are not fully understood. Nevertheless, the trend toward decentralized industrial development is clear. The significance of ready access to high-type express highways must not be overlooked in projecting the probable loca- tion of future industrial uses. Thought should also be given to the probable pattern of land-use zoning which will affect the locational pattern of industry and business. Industrial decentralization and the recent rapid expansion of Urban populations in to the suburbs have been made possible by wide spread ownership of private motor vehicles. Only recently has automobile ownership become so common that a new plant can be located without regard to the convenience of mass transportation, so long as a large enough parking lot is provided to accommodate the cars of the work force needed to man the plant. Automobile Ownership – The origin-destination survey collected data on existing car ownership in each zone of the Omaha Metropolitan Area. These data can be related to populations in each zone to develop car ownership ratios which may show correlation with average in come, population density, transit service, and other variables. Within the past 10 years the ownership of automobiles within Urban areas has increased to the point where it is possible to predict the saturation level in many suburban communities. At the time of the 1950 census, approximately 30 per cent of Omaha's residents were in the age brackets under 16 years of age, or over 70 years. ' of potential au to drivers Very few of these people drive. Of the “eligible age group' (70 per cent of the population), some are ineligible to drive because of physical or mental impairment, or for other reasons (in prison or hospitals, etc.). While no accurate figures are available, three or four per cent of the population doubtless falls in this group. Most of the remaining populace is actually licensed to drive. (There are some - 63 - eligibles who do not want to drive, of course.) But not all licensed drivers have exclu- sive use of an automobile. A study of licensed drivers versus car ownership shows that car ownership has approached this condition at a very slow rate in recent years. The optimum expected ratio of cars to licensed drivers appears to be about 1.25 drivers per car when all eligible-age persons are licensed to drive. No community has yet reached this level of car ownership on an over-all basis. The results of the above analysis establish that about 70 per cent of the population is of driving age in Omaha, and that the proportion actually eligible for licensing is probably about 90 per cent of this group. Car ownership probably cannot be expected to exceed a ratio of one passenger vehicle to each 1.25 licensed drivers, so it is reasonable to predict maximum possible car ownership at roughly one car to every two persons in the entire Metropolitan Area population. This rate of ownership can be taken to represent practical saturation and, as such, may be considered a "limit” that will be approached gradually and may never actually be realized as illustrated in Figure 43. Future car ownership can thus be realistically related to future population distribution. Trip Length and Travel Time In the modern city, distance tends to be measured in terms of travel time rather than miles. As highways and streets are improved all parts of the community are brought closer together in sofar as travel time is concerned. It is likely that an expanded highway program of express highways will come into being in the next few years which will permit rapid movement throughout the city. Trip time is one of the important impedances to travel. Reduction of travel time will tend to generate more travel between all parts of the city. A reasonable estimate of trip-time between zones can be developed for future years by giving appropriate weight to highway and transit improvements which may reasonably be expected to take place. Characteristics of Internal Trips Some a spects of the future city can be predicted with reasonable certainty, as has just been pointed out. If the characteristics of 1955 travel are related to these con- ditions as they existed in 1955, it is possible to derive factors which can be applied to the predicted future patterns of population and land use. By this means the probable patterns and volumes of future travel can be estimated. In the following an alyses the problems of internal trip generation have been developed in these categories: - 64 - Trips to and from the CBD Work trips Transit riders Auto drivers and passengers Average auto occupancy Non-work trips Trans it riders Auto drivers and passengers Average auto occupancy Work trips generated between all zones except CBD Residential distribution of labor force Transit riders Auto drivers and passengers Average auto occupancy Distribution of employment Transit riders Auto drivers and p assengers Average du to occupancy Non-work trips generated between all zones except CBD Population distribution Transit riders Auto drivers and p assengers Average duto occupancy Special generators (shopping centers, public parks, other) Transit riders Auto drivers and passengers Average auto occupancy Truck trips Population distribution Industrial generators - 65 - Trips Generated in the Central Business District The Central Business District is a very special part of the city. Many of the services offered and functions performed there are not offered or performed anywhere else in the city. The city government is centered there, transportation terminals are con- venient to it, important local institutions are headquartered there, and a wider variety of retail service is available there than in any of the neighborhood shopping districts. Because it is unique, the CBD exerts a strong attraction on all parts of the city. Even at the external cordon, a large share of traffic is found to be going to or from the CBD. Because it is the most popular destination in the city, the CBD is the focus of the public transit system. All major bus routes converge on the CBD and their heaviest patronage — a third of all transit riding — has origin and destination in this Center. Also because the CBD attracts so many people, it is congested. This con- gestion extends not only to moving persons and vehicles, but to terminal space as well. Parking space is at a premium, as every driver has discovered. The several conditions just outlined contribute to the mode of travel chosen by persons who visit the CBD. The fact that transit service to this area is better than . to all other areas, places public transportation in its best competitive position with regard to auto travel. Also the high cost and in convenience of terminal space for the motorist tends to depress the use of the private car. CBD travel thus requires a more specialized analysis than most other zones. Work Trips – The CBD is by far the most important center of employment in Omaha. It is estimated that about 22,000 persons were employed in the CBD in the fall of 1955. These people generated approximately 45,600 trips for work purposes each day, as passengers on buses or as drivers and passengers in cars. (Work trips, as defºned in this analysis, consist of all trips made to work plus all trips from work to home.) All work trips are performed by persons in the labor force. Since the propor- tion of labor force to population is not constant in each area of the city, but varies with income level, marital status, age group, and the like, it is only logical that trip analyses - 66 - º T º O O O º - - - - 7-3 || 0 |2 3-5 15 & 19–21 22-24, 25–27 25–30 º-33 34-55 tº 59. PEAK FOUR Dº I V N G | ME. M. N. L. E. S. Figure 29 WORK TRIPS GENERATED IN CBD ALL MODES OMAHA TRAFFIC STUDIES WILBUR SMITH 8 ASSOCIATES should be related to the labor force rather than to all persons resident in each zone (See Appendix F for 1955 population estimate in Omaha Metropolitan Area.) It has already been noted that travel time is a useful measure of trip length. The use of travel time tends to iron out the special influences of congestion and restric- tion which apply to travel on some routes and do not apply to movement on others. In Figure 29 the effect of travel time on the generation of work trips in the CBD has been plotted, disregarding mode of travel, and relating rate of trip generation to peak-hour auto driving time. The data are plotted in terms of trips per thousand labor force in the zone of origin or destination outside the CBD, per thousand employees - 67 - THIS CURVE APPLIES ONLY TO ZONES WHICH HAVE TRANSIT SERVICE. AUTO TRIP OCCUPANCY, C.E.D., WORK TRIPS = 1 - 4 - O º -----> -- ~ Bºº ----> -- ~~~. Cº-º-º- Figure 30 PROPORTION OF WORK TRIPS TO AND FROM CBD BY TRANSIT OMAHA TRAFFIC STUDIES WILBUR SMITH 8 ASSOCATES within the CBD. A smooth curve has been fitted to the plotted points to show the characteristic effects of distance (travel time). Deviation of plotted points from the curve is no greater than expected from sample data. The curve was leveled off at an arbitrary point in order to give at least minimum weight to trip potential from every zone within the Metropolitan Area. - 68 - Figure 30 has been Prepared to illustrate the influence of car ownership on travel by transit to the CBD and applies only to zones served by transit. Car ownership has been expressed in terms of Persons in the labor force per car owned. This curve is indirectly related to economic status, which, in turn, is related to geographic distribu- "9", since higher income groups usually live well out towards the periphery of the city while lowest incomes are clustered near the core. Careful investigation of the ratio of passengers to drivers fails to show any relationship to length of trip for work travel to and from CBD. Average auto occupancy was found to run about 1.4 persons per vehicle. Non-Work Trips – Non-work trips generated in the CBD numbered about 56,500 for travel by auto drivers and bus and auto passengers. The entire Metropolitan Area Population has contributed to non-work travel, rather than a particular stratum as in the case of work trips and the labor force. Very general investigations were made to find if a further breakdown of trips by purpose would yield significantly different results, and most non-work Purposes were found to follow the same general pattern of distribution. The analysis of non-work CBD trips has been related to automobile driving time at the peak-hour, as was done with work trips. Off-peak time was also investigated but showed no significantly different correlation. Figure 31 illustrates the effect of travel time on the rate of non-work travel to the CBD by each 1,000 residents in the Metropolitan Area. A smoothed curve has been drawn through the plotted data, with the rate of travel to the more remote zones slightly exaggerated so that the curve can be extended to give some weight to travel from zones even farther away when the curve is applied to an expanded Metropolitan Area. Deviations from the segment of smoothed curve out to 30 minutes are no more than are to be expected from sample data. Car ownership also exerts an influence on mode of travel chosen for non-work trips to the CBD. Figure 32 shows that within six minutes driving time from the center of the CBD, car ownership appears to have a more negative effect on transit use than it has at greater distances. However, most zones with in six minutes distance from the CBD are areas of low car ownership. It has also been found that trans if use does not reach its maximum potential with in six minutes of the CBD because waiting time and traffic congestion make walking almost as fast as riding. Car use is not so seriously reduced by these factors. - 69 – - º |- - - |- - |-- O C. º -- | |-- º |- º |- º º O E- - O - * > 0-2 5-5 ſº-ſº º-º º 25–27 25-50 º-ºº ºf ººº ºº: º 'º Cº-ºº º 'º - E. G. Figure 31 NON-WORK TRIPS GENERATED IN CBD ALL MODES OMAHA TRAFFIC STUDIES WILBUR SMITH 8 ASSOCIATES Vehicle occupancy of automobiles making non-work CBD trips was found to average 1.4 persons per car, the same as work trips. This occupancy ratio applies regardless of length of trip. Intra-zone Trips – A considerable volume of travel is made entirely within the CBD. Since the area of the business district is not great it is probable that most intra- zone travel is performed on foot. Even so, about five per cent of all auto and passenger trips generated by the CBD begin and end within the area. Intra-zone transit travel is neglibible. - 70 - THESE curves APPLY on-LY TO ZONE's S-RVED BY TRANST. AUTO TRIP OCCUPANCY, C.E.D. Non-woºk TRIPS = 1 - 4 º º - - º |- - T |- º |- |-- º -----> -ºº º Figure 32 PROPORTION OF NON-work TRIPS TO AND FROM CBD BY TRANSIT OMAHA TRAFFIC STUDIES WILBUR SMITH 8 ASSOCIATES Works Trips Generated Outside the Central Business District Every zone in the survey area is the place of work for at least a few persons. Zones which are completely residential in character are the place of employment for domestic help, nurserymen, delivery men, etc. Schools employ teachers; churches employ ministers and an office staff. Neighborhood stores employ salesmen and accountants. Construction work – new homes, roads, sewers, etc. employ a multitude of skilled and semi-skilled laborers. Such non-industrial employment throughout the city constitutes a large percentage of the work opportunities in the community. - 71- Industrial and commercial employment is much more concentrated than the more general classes of work just mentioned. Some sections of town are devoted almost exclusively to industry and manufacturing and contain little or no resident population. Yet the patterns of trip generation to industrial and non-industrial employment are very similar so that work trips of all sorts may be effectively grouped for analysis. The places of employment are only half the picture, however. All employees are drawn from the labor force in the resident population. There is a negligible inter- change of work trips between centers of employment (except for the movement of raw materials and finished or semi-finished goods). Thus, work travel involves two separate populations -- the labor force and the jobs (employment). Work Trips by Labor Force – In the following and lysis, it has been convenient to study travel patterns separately for labor force and for employment. The results of the two studies are not alike for at least two reasons; (1) There are more persons in the labor force than there are active jobs -- a portion of the labor force is always un- employed, is on vacation or sick leave, or does not work every weekday (the Origin- Destination Study covers the average weekday condition); and (2) major sources of employment are he avily concentrated toward the center of the Metropolitan Area, while the reverse is true of the residences of the labor force. The generation of work travel between zones of residence and places of work is strongly related to length of trip and the number of work opportunities. The labor force in any zone may be considered eligible for any of the jobs available in all zones in the city. Rate of travel between a pool of labor force and sources of employment then becomes directly proportional to the number of jobs in each zone and inversely pro- portional to the length of trip. In order to derive a consistent behavior pattern for work travel, it is necess dry to consider all regional employment as part of the job potential in devising trip distribu- tions for labor force in each zone. In Figure 33 the rate of travel for work trips between labor force and places of employment has been plotted by determining the cumulative percent age of jobs within successive increments of travel time. The amount of travel between zones is stated in terms of trips per 1,000 labor force per 1,000 jobs (exploy- ment) by distance increments. - 72 - READ RATE OF TRIP GENERATION AT EACH 3-minute interval FRow 2 one, Based on accumul-ºr-D PER CENTAGE OF EMPLOYMENT ºn tº sººn CE FROM - ONE OF RESIDENCE. curve DoE’s NOT PROVIDE FOR EST IMATES or in TRA-ONE TRAVEL º º --- º zo Cº- ºr ºººº Gº º º º sº. Cº- Figure 33 WORK TRIPS TO AND FROM PLACES OF RESIDENCE OMAHA TRAFFIC STUDIES WILBUR SMITH 8 ASSOCIATES Mode of travel to and from sources of employment located outside the CBD is more strongly influenced by auto ownership than were CBD work trips. Transit service is not uniformly good from all residential areas to each source of employment -- it may not even exist. Furthermore, parking space is usually free and readily available. Many large employers have found it highly desirable -- or even necessary -- to provide adequate free parking space for employees. Figure 34 shows the effect of car ownership on the use of transit for work travel. - 73 - - º - º º |- -- T- º |- |- º º |- º |- º º º |- |- º |-- º º |- |- º |- (- º |- ºº º º 'º º Aº ºº Figure 34 PROPORTION OF WORK TRIPs MADE BY TRANSIT OMAHA TRAFFIC STUDIES WILBUR SMITH 8 ASSOCIATES […] º º º In º º º º º º º º L. º […] Fº º º º º º º º- C º º in º º º º º º º º º |- º º º º READ RATE OF TRIP GENERATION AT EACH 3 - MINUTE INTERVAL FROM ZONE, BASED ON ACCUMULATED PERCENTAGE OF LABOR FORCE WITH IN DISTANCE FROM ZONE OF EMPLOYMENT CURVE DOES NOT PROVIDE FOR EST IMATES OF INTRAZONE TRAVE L. º M : s º-ºº-25 Mose auto delves.s and pass, MoRE – trainst Rupe Rs) º sº º º ſº º º Cº. 4 ºf ººººººº dº º ſº Aº Aº Aº Fºº º Figure 35 TRIPS TO AND FROM PLACES OF WORK ALL MODES OMAHA TRAFFIC STUDIES WIL BUR SMITH 8 ASSOCIATES Auto occupancy has also been evaluated for work trips made between all zones except the CBD. Again, trip length does not appear to modify occupancy. Occupancy was found to average 1.2 persons per car. Work Trips Generated by Employment – The same variables used to evaluate travel from place of residence to all sources of employment may be used to study the distribution of trips between a pool of employment and the sources of labor supply. In this case, the rate of trip generation is weighed against the accumulated percentage of labor force within each successive increment of peak-hour driving time as shown in Figure 35. Rate of trip generation is expressed in terms of trips per 1,000 persons employed in the zone per 1,000 persons in the labor force at each successive incremer of travel time. - 75 - NOTE- READ RELATIVE RATE OF TRIP GENERATION AT Each - M-NUTE INTERVAL FROM -o-E. DERivº TOTAL RELATIVE TRIPS. To ZONE. David E. Known TOTAL TRIP volu-E GENERATED In 20se a total Relative tales. MULTIPLY EACH RELATIVE INTERZONAL VOLUME, By rºus Facton. To PRODuce "Finst APPROximation" OF MOM-wºº Tºlº vol. U-E. PEAK- HOUR TRANSIT RIDING, TIME - MINUTES Figure 36 NON-WORK TRIPS ALL MODES OMAHA TRAFFIC STUDIES WIL BUR SMITH 8 ASSOCIATES The proportion of these trips which would be made by transit is related to the ratio of persons to cars in each zone from which employment is drawn, as shown in Figure 34. Infra-Zone Work Trips – The zones into which the Omaha Area has been sub- divided are roughly the same size except for the CBD, which is smaller than most. Since the zones are of reasonably uniform size, they tend to generate similar proportions of trips which have both origin and destination entirely within them. About 4.5 per cent of the auto driver and passenger trips are in this intra-zone category. The principal - 76 - exception is Zone 96 which encompasses the town of Bellevue. Intra-zone movements account for about 15 per cent of driver and passenger work trips in the zone. Only about 1.0 per cent of the transit rider trips for work purpose are intro- zone. Workers without cars doubtless prefer to walk to destinations within the zone since time spent walking to and from the transit stop and waiting for the vehicle to ap- Pear would often be greater than time required to make the trip on foot. Cost of the trans it ride is also an important factor. Non-Work Trips Generated Outside the Central Business District Non-work trips between zones are largely inter-residential in character except for shopping and business travel and trips for special purposes. The pattern of local shopping and recreational trips is similar to inter-residential travel and can be related to population sources with reasonable accuracy if allowance is made for the number of such trips. In Figure 36 the typical pattern of non-work trip generation has been developed, as related to peak-hour driving time. A transit time scale is also shown (assuming half the average speed attained in private cars). The transit scale shown in Figure 37 is only approximately correct, but is adequate for use in elvauating the proportion of non- work trips made by transit. Relatively few non-work trips are made by trans it. A very high proportion of this travel is generated in nearby zones, and the average trip is much shorter than work trips or CBD trips. Vehicle occupancy at 1.4 persons is higher than work trips (except to CBD). Many of the auto passengers are minors accompanying parents and the trip would be considered in convenient on the bus even if good transit service were available. Infra-Zone Non-Work Trips – Intra-zone travel is a higher proportion of non- work trips than of work trips, due to the local nature of much non-work travel. About 8 per cent of the driver and passenger trips generated in each zone, fall in the infra-zone category. An exception is the town of Bellevue in which the proportion is about twice as high. Intra-zone transit trips make up only about 2 per cent of the non-work transit travel, again due to the unreasonable time and cost relationship between walking and transit riding for very short movements. - 77 - Figure 37 NON-WORK TRANSIT RIDERS PERCENT OF INTER-ZONAL MOVEMENT BY TRANSIT VERSUS PEAK-HOUR TRANSIT TIME FROM. C. B.D. OMAHA TRAFFIC STUDIES WILBUR SMITH 8 ASSOCIATES Trips by Commercial Vehicles Truck trips have been analyzed in two categories. (1) Travel generated in residential zones (service trips — deliveries, repair services, etc.). These trips make up a large volume of travel and account for approximately 40 per cent of truck origins and destinations. (2) Travel generated between industrial zones and to and from other zones of employment. These trips make up the remaining truck movement. Distinction has also been retained between trips by light trucks (pickups and panels) and heavy trucks since they are basically different types of carriers. - 78 - LIGHT TRUCKs (PANELS AND PICKUP's) HEAVY TRUCKS (ALL OTHERS) Figure 38 TRUCK TRIPS GENERATED BETWEEN RESIDENTIAL POPULATIONS VERSUS TRAVEL TIME OMAHA TRAFFIC STUDEs WILBUR SMITH 8 ASSOCIATES SMALL TRUCKS (PICKUPS AND PANELS) LARGE TRUCKS Figure 39 TRUCK TRIPS GENERATED BY INDUSTRY AND EMPLOYMENT OMAHA TRAFFIC STUDIES WILBUR SMITH 8 ASSOCIATES Figure 38 shows the pattern of truck travel related to population and travel time for trips generated between residential zones, based on average patterns of move- ment generated in a number of different residential zones. It is interesting to note that the relative rate of trip generation at any distance is the same for both light and heavy trucks, although light truck movements are almost three times as frequent as those of heavy trucks. The similarity is probably due to the use of heavy trucks for delivery service in the same way that light trucks are employed. Fuel trucks constitute the pre- dominate he avy-fruck movement in most residential areas and their delivery patterns conform to those of other types of delivery services. Figure 39 develops the pattern of truck travel between centers of employment. Trips from industrial zones have been related to the number of persons employed in each zone in the city. Good correlation is a chieved in this way, as shown on the exhibit. The heavily industrialized zones the Inselves generate trips at somewhat different rates than those developed from the employment ratios, but there are relatively few of these zones and each must be considered a special case. The stockyards, for instance, do not generate truck trips within the city in proportion to the amount of em- ployment in the yards. This may be due to the greater dependence on out-of-area trucks and on the amount of freight handling performed by rail. On the other hand, Zone 01, located between the CBD and the Missouri River, generates truck trips at nearly twice the employment ratio. There is virtually no residential Use in this zone. Much of the movement is generated by warehousing and similar uses which create a high proportion of truck trips in relation to employment. Again, this is a special case which is better an alyzed apart from the general treatment accorded less important generators. It is somewhat surprising to note that the rate of heavy truck travel between zones decreases more rapidly than light truck travel. Heavy truck travel may be related to the concentration of heavier industries toward the center of the city, but his is merely speculative. A very detailed analysis of truck travel would be required to resolve this problem. Infra-Zone Truck Trips – Most urban truck trips are very short. Delivery services usually consist of a series of short trips in a single circuit from warehouse to commercial establishments and residences. Infra-zone trips which begin and end within the same zone make up approximately 18 per cent of internal truck movements throughout the study area. - 8 l - Characteristics of External Trips Travel between a city and the areas outside its metropolitan limits makes up an important fraction of the daily traffic flow although the amount is relatively small when compared to all vehicle trips performed in the Metropolitan Area. The amount of this travel is directly related to the number of persons who reside at various distances from the city and is inversely related to the travel distance (or travel time) between these populations and the Metropolitan Area itself. The volume of daily traffic inter - change between a city and its ‘‘h interland'' is also strongly influenced by the proximity of each outlying district to other large communities. In Omaha about 55,000 vehicle trips which began or ended in the study area had one terminus outside the external cordon at the time of the 1955 survey. In addition to these, nearly 6,000 vehicles passed through the Metropolitan Area without stopping (see Table 3). Extern al travel thus accounted for about an eighth (13 per cent) of the 463,721 vehicle trips performed in the Metropolitan Area on an average 1955 weekday. Table 9 Omaha Traffic Studies EXTERNAL TERMIN | OF LOCAL TRIPS CROSSING OMAHA CORD ON – 1955 Trip Terminus Passenger Cars Trucks Total Douglas & Sarpy Co. (outside Cordon) 12,131 2,528 14,659 Council Bluffs 15,450 2,260 17,710 Other Pottawattamie Co. 1,700 345 2,045 Cmaha Standard Metropolitar, Area 29,281 5, 133 34,414 Other Nebraska and lowa 14,529 4, 117 18,646 Other States 1,360 580 1,940 Total Trips 45,170 9,830 55,000 - 82 - About two-thirds of these external trips originated with in the external portions of the Omaha Standard Metropolitan Area, as defined by the U. S. Bureau of the Census. Nearly a third are made between Omaha and the other counties in Nebraska and Iowa. The remainder (less than four per cent) have origin or destination in other Std fes. It is interesting to note that the ratio of trucks to passenger cars increases with length of trip. Only about 15 per cent of the cord on traffic generated within Douglas, Sarpy and Pottawattamie Counties is composed of commercial vehicles. Some 22 per cent of the remaining Iowa and Nebraska vehicles are trucks. About 30 per cent of the traffic to and from states other than low a and Nebraska are trucks. Through Trips – Fewer than 6,000 trips pass entirely through the Omaha study ared on the average day. Most of these through trips (83 per cent) are passenger cars. About half of the “through” auto trips have one or both termini within the three-county Standard Metropolitan Area. About 45 per cent of the trucks also fall in this category. Through travel which is not actually related to the Omaha Area is thus found to account for less than five per cent of the trips encountered at the 1955 cordon stations. Table 10 Omaha Traffic Studies THROUGH T R |PS — 1955 Trip Terminus Passenger Cars Trucks Total One or both ends in 3-county Standard Metropolitan Area 2,437 558 2,995 Trips with neither end in Standard Metropolitan Area 2,421 450 2,871 Total Trips 4,858 1,008 5,866 - 83 – TRIPS GENERATED IN NEBRASKA AND AREAS WEST THROUGH NEBRASKA CORDON STATIONS TRIPS GENERATED IN IOWA AND AREAS EAST ACROSS Missouri River Figure 40 EXTERNAL AUTO TRIPs GENERATED BY OMAHA METROPOLITAN AREA OMAHA TRAFFIC STUDIES WILBUR SMITH 8 ASSOCIATES Area Tributary to Omaha — The origin-destination data show the volume of travel generated between Omaha and each zone and county in the states of Nebraska and lowa and to neighboring states. A straightforward procedure may be used to relate trip volumes to population classifications in the several are as , which will establish the relative attraction of Omaha to these areas. Automobiles, people, dwelling units, labor force, or other populations may be fested for reflections of this drawing power. Figure 40 shows how automobile trips at the cordon can be related to automo- bile registration and distance. Trips are generated at high rates to zones and counties immediately adjacent to the Omah a Area. Trip rates decrease uniformly as distance (driving time) increases. It is especially interesting to note that trips are generated at a much higher rate in are as west of Omaha than in areas east. Beyond three and one-half hours driving time the rate of attraction to western areas is nearly three times the attraction to the east. This is largely due to the competition of other important cities east of Omaha which offer an equal or greater number of attractions. Principal among these competitors are Kansas City, St. Louis, Minneapolis-St. Paul and Chicago. The only western cities comparable in size to Omaha are Oklahoma City and Denver which are nearly twice as far away as important eastern competitors. Another condition which doubtless contributes to the low rate of travel to areas east of Omaha is the Missouri River barrier. Furthermore, Council Bluffs provides urban services to traffic attracted to the Omaha Area. The apparent rate of travel to the east is thus deceptive, since Council Bluffs and its urbanized suburbs is a part of the Omaha Metropolitan Area and is the focus for much external travel. Council Bluffs population generates low a trips at higher rates than the Omaha population because travel times (trip lengths) are shorter. Figure 41 illustrates the generation of commercial travel to outlying areas and is related to the numbers of people resident in those areas. Again, the western popula- tions create travel greater than eastern counties, and the rate of trip generation decreases more slowly toward the west. Competition and incomplete information on Iowa portions of the Omaha urban area are the principal factors contributing to these differences. - 85 - TRUCK TRIPS GENERATED IN NEBRASKA AND AREAS WEST THROUGH CORDON STATIONS TRUCK TRIPS GENERATED IN IOWA AREAS EAST ACROSS MISSOUR RIVER Figure 41 EXTERNAL TRUCK TRIPS GENERATED BY OMAHA METROPOLITAN AREA OMAHA TRAFFIC STUDIES WILBUR SMITH 8 ASSOCIATES Figure 42 INTERNAL DISTRIBUTION OF EXTERNAL TRIPS AT CORDON OMAHA TRAFFIC STUDIES WILBUR SMITH 8 ASSOCIATES Since data for the Council Bluffs—Pottawattamie County segment of the Metropolitan Area are not complete, it is not possible to refine these analyses to describe the characteristics of competitive attraction between Omaha, Kansas City, St. Louis, and other cities in the region. Insofar as the City of Omaha is affected, the curves developed in Figures 40 and 41 are a good measure of the city's trip attraction. Internal Distribution of External Trips – Within Omaha an orderly pattern of trip generation between cordon stations and internal zones is apparent when trips are related to the combined labor force and employee populations of successive increments of distance from each station, or group of stations, serving a rather well-defined segment of the peripheral areas. These relationships are illustrated in Figure 42. The distance measure in this case is related to the cumulative percentage of all population (labor force and employment, combined) at successive distance intervals. The curves shown in this drawing apply to all zones except the CBD. Labor force and employment have been combined to represent the attraction of both residential and commercial-industrial uses in each zone. Other factors of residen- tial use were tested in combination with zone employment (cars owned; number of dwell- ing Units; total population) but none were found to be as well related as labor force. The curves shown in Figure 42 represent relative values, and both are indexed to 100 trips per 1,000 population (combined labor force and employment) at the station itself. Actual volume of auto travel across the cord on is several times that of trucks, of C O U r S e. Passenger-car trips tend to be generated at a very high rate to internal popu- lations immediately adjacent to the interview stations. Trips which penetrate the first 20 per cent of urban population are generated at a gradually decreasing rate to the remaining sectors of the city. The relationship shown on the drawing is somewhat deceiving, however, since the percentage of population with in successive time increments (three-minute and five-minute intervals of driving time) increases rapidly toward the center of the city, due to higher population densities and to the increasing a mount of land ared within successive intervals. Truck travel has also been related to the labor force and employment popula- tions. The rate of truck-trip travel does not decrease as rapidly to internal areas close - 88 - to the cordon as auto trips from nearby populations to the more remote zones. Most of the principal truck generators in Omaha are centrally located, while there is relatively little generation in zones near the cordon. External Trips in Central Business District – The Central Business District affracts a disproportion ate share of the external traffic and must be given special con- sideration. Counties adjacent to the three-county Omaha Standard Metropolitan Area generate about 15 per cent of their Omaha travel in the CBD. As distance from Omaha increases, higher proportions of traffic Gre destined to the CBD. The CBD exerts maxi- mum attraction to areas about 300 miles distant, from which about 40 per cent of all trips have a downtown terminus. Beyond this distance the relative attractiven ess of the CBD declines but data are too few to establish reliable trends. External auto and truck trips both reflect the influence of trip length just de- scribed. The proportion of truck trips generated in the CBD is somewhat less than auto trips from nearby zones but peaks at about the same proportion. The relative proportions of CBD and non-CBD traffic are reasonably consistent for trips generated across the Nebraska cord on or the Missouri River Bridges. – 89 - PART V TRAVEL IN CMAHA METROPOLITAN AREA – 1960 AND 1970 The Omaha Metropolitan Area is experiencing a relatively rapid rate of growth. As shown in Table 1, the city population increased about 12 per cent between the 1940 and 1950 censuses. Probably the best measure of Omaha's over-all growth is the com- parison of population statistics for the three-county Standard Metropolitan Area defined by the U.S. Bureau of the Census (Douglas and Sarpy Counties in Nebraska; Pottawat- famie County in Iowa). Figures for the Standard Metropolitan Area are not influenced by changes in city-limit lines as are the city population reports. The Standard Metro- politan Area population increased approximately 12.5 per cent during the 1940 - 1950 decade. For the decade 1950 to 1960 a more rapid rate of growth has been predicted, based on tentative estimates which place 1955 Metropolitan Area population at over 400,000, a rate of growth since 1950 which would result in about 19 per cent increase by 1960, or approximately 435,000. This rate of growth, continued to 1970, would result in a metropolitan population of 515,000 persons by that date. These population values, although maximum estimates, have been used as the basis for future traffic projections. It is important to bear in mind that the travel patterns developed in these studies do not relate to particular years, but represent travel which would be generated by populations of the size upon which the analyses are based. Thus, if the population increase which takes place over the next 15 years should exceed or fall short of the growth rates used in these studies, the trip patterns projected here would be realized at an earlier or later date when these populations were reached. An appreciation of this concept will greatly increase the usefulness of the projected trip data. Future Study Area The 1970 population estimate, 515,000 persons in the Standard Metropolitan Area, represents a 40 per cent increase over population in the area at the time of the 1950 census, and is approximately 29 per cent greater than at the time of the 1955 survey. Most of the increase will be Urban, since rural densities in lowa and Nebraska have - 90 - remained virtually unchanged for many years. It is clear that such urban increase is not likely to take place within the limits of the 1955 study area. The anticipated urbanization around Omaha is not expected to extend beyond the limits of Douglas and Sarpy Counties, but a large amount of rural area within the counties will become urbanized. It has seemed desirable, therefore, to incorporate all of Douglas and Sarpy Counties in the Omaha urban study area. Council Bluffs, and adjacent low a communities, are presently with in the Omaha sphere of influence. Study of Omaha's future travel patterns must take into account the further urbanization of these areas and the traffic which they will contribute to Metro- politan Omaha. Although detailed travel data are not available for movements within Council Bluffs and the rest of Pottawattamie County, it is desirable to extend traffic projections to include these communities. For the sake of consistency, all of Pottawattamie County has been included in a three-county study of the Omaha Standard Metropolitan Area. Projections of Population Distribution The characteristics of trip generation derived in Part IV of this study were re- lated to the populations resident or employed in each of the zone-subdivisions within the Omaha Study Area. These characteristics can be fitted to changes in population dis- tribution to produce reasonable projections of travel likely to occur under revised circum- stances. The first step, then, in developing future travel patterns, is the careful deter- mination of future populations in the zones. The distribution of population increases in most modern American cities is largely peripheral. Study of recent population changes indicates the direction that new growth is taking and the intensities of land use which can be anticipated. The least amount of change will take place in those areas already well built-up -- unless they are scheduled for clearance and reconstruction to different population densities. Reasonable patterns of future population distribution have been developed for the years 1960 and 1970, assuming Metropolitan Area populations of 435,000 and 515,000 for those years. A generalized pattern of population increase has been projected, giving - 9 || - the fullest possible account to recent trends and proposed developments presently under consideration. Within the population of persons there are other changes taking place which must also be projected. Car ownership is still increasing in most zones, although satu- ration has nearly been reached in some parts of the city. Thus, the ratio of cars to persons must be considered separately for each zone. The same is true for estimates of dwelling units, labor force and employment. The population distributions which have been developed are tabulated in Appendices G and H in this report. Auto registrations reflect the proportion of travel that is performed by car. Car ownership in 1955 was determined at the time home interviews were made and those data provide a reference point from which to project. Auto registrations have increased very rapidly during the past few years, but there are valid reasons to believe that future increases will be much less dramatic. Much of the post-war growth reflected pent-Up demands for new cars which could not be purchased during the war. A rising level of family income has contributed to a continuing high rate of vehicle increase, bringing ownership to near-saturation in some parts of the city. Future growth will be more and more dependent on population increases as the saturation level is reached. The over-all registration trends for the Omaha Metropolitan Area are indicated in Figure 43, as they relate to population and the anticipated “saturation level,” a ratio of one car to every two persons in the area. Average car ownership in the Omaha Area will amount to about 2.7 persons per car by 1970. In 1955 there was an average of 3.3 per- sons per car in the study area. The total number of trips performed by residents of the Omaha Metropolitan Area was found to be closely related to the number of dwelling units in each zone. Only passenger car and trans it trips were reported in the survey, of course, and the number of such trips per dwelling was found to increase as distance from the CBD became greater. The ratio of dwellings to persons in each zone for future years has been slightly modi- fied from the ratios determined in the 1955 survey, in accord with anticipated land-use developments. The labor force population was found to be related to persons and to dwelling units. The proportion of the population in the labor force is greatest in a partment districts which contain many single persons and young married couples. It is least in - 92 - POPULATION TRENDs Figure 43 Population AND CAR REGISTRATION TRENDS Om Ah A STANDARD METROPOLITAN AREA OMAHA TRAFFIC STUDIES wil-BUR SMITH 8 ASSOCIATES peripheral areas occupied by young families. Consideration was given these factors in developing the distribution patterns of the future labor force population. - 93 - The number of iobs (available employment) in each zone is the most difficult of the Population estimates. Most of the problem centers about the distribution of new iobs, since few established areas are expected to lose employment. Some new jobs are created in residential zones as the number of people living there grows larger. These are primarily “service” iobs -- house maids, gardeners, maintenance men, and so forth -- whose number is closely related to the number of people resident in the zone. The location and amount of this employment can be anticipated with good reliability. The probable location of new industrial employment is much more difficult to forecast. In recent years there has been a very strong trend toward decentralization of new industrial plants. Modern plant layout has encouraged the design of one-story, sprawling factories which require a large amount of inexpensive land if they are to be constructed economically. Most modern plants are built on sites which contain adequate land area in reserve for plant expansion, plus a great deal of area for employee parking. At many of the decentralized plants the entire work force is expected to arrive on the job by car, and ample off-street parking space is provided to accommodate all of the plant's workers. The development of new express highways will make land near interchange points very attractive to new industrial development, especially if large undeveloped tracts are still available near these points of access. Therefore, in projecting industrial employment to 1970, considerable attention has been given to the tentative locations for proposed new express highways. Some areas directly west of Omaha (Zone 106) are al- ready expanding in very active fashion. The estimates of future employment which have been projected are, at best, only approximations of the pattern of employment which will develop. Transportation Facilities – 1970 Any change in the over-all quality of traffic flow in the Omaha Area is certain to affect the rate of traffic increase and to influence the patterns of trip origin and destination. This is equally true of transit and auto travel. Any material improvement in the efficiency of mass transportation would improve its competitive position with auto travel, especially if the efficiency of auto travel was not improved at the same time or was improved to a lesser degree. - 94 - In general, it is safe to predict that measures taken to improve traffic operat- tions will result in traffic in creases exceeding those which may be attributed to popula- tion and vehicle growth. By 1970 m any sections of an urban expressway system will probably have been completed. The improvements to highway travel which thus result will have a pro found effect on the patterns of traffic generation within the metropolitan C, re C. The development of major new highways will have an important influence in the direction of future urban growth. Just as the construction of railroads a hundred years ago encouraged the settlement of the country along their rights-of-way, so will the ex- press highways radiating from the central city speed the development of rural are as beyond the present limits of Urbanization. The distribution of future populations de- scribed above has had to anticipate the approximate routing of these new arterials. This process is inherently redundant, in that the populations so distributed are the generators of future traffic desires which, in turn, help to justify the anticipated route location. In the case of Omaha, most of the tentative expressway routings have been developed to serve present pattern s of growth and the extension of this system will simply expedite the trend. Public transportation by mass carriers is expected to make use of the new express highway system; consequently, mass transit may be expected to improve its operating perform ance accordingly. However, by its very nature, public transportation lacks some of the convenience values found in the use of the private automobile. Transit operations must somehow be improved to exert a more competitive position with the automobile if transit is to hold its own in this growing metropolis. In every year since the end of the war, ublic transportation has lost patron age. Daily use of transit vehicles in 1955 was ſess than half the use experienced in 1944 at the time of the earlier survey. During those years the urban population in creased by approximately 15 per cen f. The loss of patron age experienced by the Omaha Transit Company is by no means unique. It is, in fact, the usual story in cities throughout the United States. At the national level, much thought and experiment is going in to the development of more efficient and more attractive transit operations. Transit people are certain that some amount of demand will always exist for transit service. They believe that research will develop improvements which will enable public transit to maintain a higher standard of service and thereby retain most or all of its present patron age in the are as most adaptable to transit service and even encourage additional use. - 95 - Transit service in Omaha is expected to keep pace with general improvements in transit service as they develop over the years. In deriving the trip projections de- scribed here, it has been assumed that the quality of transit service will improve at the same rate that auto transportation is benefited by new highways and traffic engineering measures. Even so, transit use would not increase in a degree comparable to auto travel because most of the new community growth is expected to take place in districts peripheral to the built-up sections of Omaha. These are the areas which are least well served by transit. Metropolitan Area Travel – 1970 The origin-destination surveys provide a measure of the number of vehicle trips that are made by residents of a city each day. These data have been found to relate quite well to a number of dwelling units in an area and the proximity of that are a to the CBD. Distance from the CBD is a crude measure of population density and relative age of development. There are valid reasons to believe that the number of trips performed by resi- dents of the average household is in creasing -- or that more of the daily travel is being made by car and bus. Car ownership -- the ratio of cars to people -- is continuing to in- crease each year in every part of the city. Increased ownership results in more travel by car, partly because the car is available for incidental driving, and partly because the opportunities for employment are broadened to include places which are easily acces- sible only by car. The resultant decrease in transit riding is much less than the in- crease in car use. Another long-range element which appears to be influencing trip volume is the trend toward a shorter work-week in most of industry. Shorter working hours increase the amount of time available for recreation and other purposes. While no measure is available with which to check this argument directly, it is not unreasonable to expect some degree of traffic in crease attributable to this source. As the Metropolitan Area increases in size, the variety of trip attractions in- creases. Improved traffic facilities will place a multitude of these attractions within easy driving time. Time is a very important element in the scheme of trip generation. Trip volumes decrease rapidly as trip length (driving time) increases, and the reverse is - 96 - also true. Thus, improved traffic facilities and high car ownership will cut heavily in- to the volume of trips presently made on foot. Even if no more trips are made by family members, more of them will be made by car. Taking the above arguments into consideration, the 1955 rates of trip gener- a tion have been increased to expected rates of generation by 1970. Anticipated in- creases are proportionately greater in zones of relatively low generation near the CBD and are small in peripheral areas where most trips are presently performed by car. rates of trip generation for 1955, 1960 and 1970 are set forth in Table l l . Table l l Omaha Traffic Studies TRAVEL BY RESIDENTS OF STUDY AREA – AVE RA GE NUMBER OF TRIPS P E R DAY PER DW Ei_L |NG UN | T - 1955 - 1960 - 1970 Distance from CBD” 1955 l to 3 minutes 3.8 4 to 6 minutes 4.3 7 to 9 minutes 5.3 l 0 to 12 minutes 6.2 13 to 15 minutes 6.7 16 to 21 minutes 7.0 Over 22 minutes 7.2 * Minutes of Auto Driving Time at Peak-Hour 4.0 4.5 5.5 6.4 7.0 7.3 7.5 The Trips per day per dwelling unit 1960 1970 4.5 5.0 6.0 6.8 7.4 7.8 8.0 Mode of Travel – The choice of travel mode is very closely related to car ownership. Length of trips is also a factor, but is partly a measure of car ownership too, since trips necessarily involve at least one zone far removed from the CBD. ownership increases with distance from the CBD, as remarked above. Car - 97 - A third element which sometimes determines choice of mode is the presence or absence of free parking space. Car travel to the CBD is inhibited by this factor, but there is no evidence that the parking problem is decisive in the generation of travel to other zones. Except for travel generated in the CBD, the designation of travel mode in these studies has been determined from the curves developed in Figures 34 and 37 in Part IV. The proportion of CBD travel by transit has been developed from Figures 30 and 32. Note that CBD work trips by trans it have been derived from the ratio of persons in the labor-force to the number of cars owned in each zone. Car occupancy is also important in evaluating the amount of traffic created by persons who travel by car. Analysis of the 1955 survey data does not show any signifi- cant variation in vehicle occupancy due to length of trip. Trips for both work and non- work purposes generated in the CBD, and all non-work trips made outside the CBD, showed average occupancies of 1.4 persons per car including the driver. Automobiles used for work trips which had no CBD terminus averaged 1.2 riders per car including driver. These occupancy ratios have been applied to 1960 and 1970 auto trip estimates without further modification. Purpose of Trip – The analysis of trip characteristics in Part IV found that work trips (trips to work and trips from work to home) exhibited a different pattern of development than trips for other purposes. Inasmuch as work trips constitute a large fraction of urban travel, the identity of these trips has been maintained in the early stages of trip projection. Other trips, except those generated to and from the CBD, and trips which ex- tend beyond the cordon, develop a reasonably uniform behavior and have been combined for analysis. Central Business District Trips – Central Business District trips have been handled apart from all the rest. It was reasoned that the volume of CBD travel will not increase in direct proportion to population increases in the Metropolitan Areas. Data from the 1944 and 1955 studies show an apparent decrease in internal CBD trip volumes which may be attributable in part to wartime employment in downtown Omaha, and may also be affected by sampling discrepancies in the two surveys. In the following analy- s is the Omaha CBD is expected to attract an increasing volume of travel over the next - 98 - 15 years, although the rate of increase will be slower than the increase affecting the urban area as a whole. An important reason for this is that most new growth will take place in peripheral areas which generate CBD travel at relatively low rates due to the adverse influence of trip length (travel time) and the competition of trade opportunities in intervening shopping centers. Approximately 100,000 internal trips, exclusive of truck trips, had one or both termimi in the CBD in 1955. These volumes are expected to in crease to approximately 136,000 trips per day by 1970 from areas with in the 1955 cordon. A volume of about 150,000 would be generated from within the three-county Standard Metropolitan Area by that date. About 31,000 of these trips would be made by transit, representing a slight in crease in volume of CBD transit trips, although transit would account for a smaller proportion of the total CBD movement in 1970 than at present. Central Business District trips have been distributed by applying the curves shown in Figures 29 and 31. The proportion of trips for work purpose was first determined by developing the average number of auto and transit work trips per employee performed by workers in the area. A factor of 1.75 trips per worker has been applied to the estimates of CBD employment for 1960 (24,000) and 1970 (25,000). The remaining trips were assigned to non-work purposes. Transit trips were separated by formula as described above (Figures 30 and 32). Auto driver trips were determined by reducing driver and passenger trips by a factor of 0.715 (1.4 persons per car). The results of these distributions are shown in Appendices I (1960) and J (1970). Intra-zone travel is estimated to amount to about 5 per cent of the internal auto driver and passenger trips to and from the CBD. No estimate has been made for intra-zone transit travel. Work Trips – Non-Central Business District work trip volumes generated in each zone have been determined by analyzing populations which represent each end of each trip. Most zones in the study area contain labor force resident in the zone and some employment. Trips by labor force are generated in the residences where they live. Trips by employment are generated at places of work. It has been assumed that trips generated by labor force are equal in number to trips generated by employment. There is more labor force than employment in the area, since some people are vacation- ing, on sick leave, or unemployed (see analysis in Part IV). On the average, labor force generates at the rate of 1.75 trips per job. - 99 - Non-Work – Non-work trips, as analyzed in this study, consist of two principal classifications: 1.) the “special generator” category, such as trips to the CBD, to ball Parks and recreation area, to major outlying shopping area, etc. and 2.) an “inter-resi- !” classification accounting for the remaining trips. Inter-residential trips in- dentia clude travel, between peoples' homes, trips to school and church, to playgrounds, to neighborhood shopping centers, and other short-trips of similar nature. Infra-Zone Trips – An important fraction of urban travel is of very short length. Analysis of the 1955 trip data showed that many of the short trips performed by cars and trucks begin and end within the same zone. Some 4.5 per cent of the work trips per- formed in each zone by auto drivers and passengers are of this type, plus about 8.0 per cent of the non-work trips. Of transit riders, about 1.0 per cent of their work trips and 2.0 per cent of their non-work travel is assumed to fall in the infra-zone category. External Trips by Omaha Residents — Many of the trips which cross the external cordon are performed by residents of the Omaha Area. Internal residents pro- bably account for 60 per cent or more of the cordon movement, since Omaha contains by far the largest concentration of automobiles with in a considerable radius. These ex- ternal trips were reported in the home interviews, and their volume contributed to the number of trips per dwelling unit which forms the basis for future trip projections. Such travel must be accounted for before internal trip as signments can be made. Total Trips – Every trip has two ends. About 80 per cent of the trips made by residents of each dwelling have one end at the dwelling. Many of the remaining trips have one end in the zone of residence at places other than the dwelling. In applying the trip generation curves developed in Chapter IV, it has been assumed that all internal person trips have one end in the zone of residence. It has also been assumed that all labor force trips are generated in zone of residence and are a part of the dwelling unit trips. Reasonable modifications have been applied to develop logical patterns of move - ment between industrial and commercial zones to which the dwelling curves do not apply. Employment and special generator trips represent the other end of dwelling unit trips, but do not account for all of them. Some of them will terminate in the zone of residence, the number depending upon the amount of employment in the zone and the proportion of employment trips which are generated at short range. - 100 - Dwelling-unit trips which do not terminate at employment or special generators have other non-work termini. The distribution of these trips to other zones is in direct proportion to the number of persons resident in each zone. The total number of trip- ends generated in each zone can be obtained by adding together the dwelling unit, employment, special genera for and non-work trips generated in the zone. Appendices K and L present final estimates of internal trip volume, including estimates of intra-zone trips, and external trips made by residents. CBD trips from Tables I and J are included in the totals. Truck Trips – Commercial vehicles constitute a highly specialized segment of urban traffic. Analysis of truck travel in Omaha showed that the volume of truck trips generated in the city could be segregated into inter-residential and industrial trip cote gories. The trip-generating factors which have been applied to develop the volume of truck travel in each zone indicate that each thousand persons resident in a zone account for 100 light and 35 heavy truck trips made in that zone each day. Industrial trips are generated by employment in residential zones at the rate of 250 light trucks per 1000 employed and 125 heavy trucks per 1000. These factors do not apply to heavily indus- trialized zones, however. Special conside ration was given to each of these important generators. Rate of truck generation for many of these zones was found to be about twice the rates just described. The average turck trip is much shorter than the average au to trip because so much urban trucking is engaged in delivery service. A high rate of infra-zone movement results. Approximately 18 per cent of the truck trips generated in each zone are of this type. No measure was made of the proportion of internal trucks at the external cord on but this is not a problem here. Internal truck trips have been projected largely on the basis of residential distribution and employment. The volumes of internal travel thus derived are not affected by the amount of external travel performed by vehicles garaged within the study area. Data for truck trips generated in each internal zone for 1960 and 1970 are shown in Appendices M and N. Special tabulations of CBD trips are contained in Appendices O and P. - 101 - Distribution of Internal Trips The distribution of trips generated in the CBD has been described above. Be- cause of the CBD's very unique position, the CBD pattern of trip generation does not conform to the patterns which may develop for travel between other internal areas. The internal area studied in the 1960 and 1970 and lyses consists of 95 zone subdivisions (including the CBD). Techniques have been developed for the logical distribution of trips between each pair of zones in this series. However, because of peculiarities in the generation patterns of work and non-work trips for each mode of travel (auto and transit), and a similar need to examine two classes of truck trips (inter- residential and industrial) the manipulation of data becomes an exceedingly complex and time-consuming mechanical process. The techniques for trip distribution are basically the same for each of the trip categories mentioned above. The distribution of trips from one zone to all others is directly proportional to the size (population) of each of the outlying zones and inversely proportional to the distance between distributor and receptor zones. These principles are modified between adjacent zones because trans it and auto travel – the only modes con- sidered here — must compete with pedestrian travel which becomes highly competitive at very short distances. Figure 33 illustrates the principle of trip distribution (work trips to and from places of residence, in this case). The rate of travel to other zones is determined by reading from curves which are related to travel time (distance) and population. The rates thus derived are relative and must be proportioned to the volume of trips available for distribution from the zone. Figure 44 illustrates the time-distance relations hips which have been developed for use in trip projections to 1970. The is ochrone lines are comparable to those shown on Figure l l for 1955, illustrating the peak hour auto driving time anticipated in Omaha by 1970. Most of the expected improvements consist of arterial and express highway construction which will greatly expedite the flow of travel into and within the central city. Comparison of the two travel-time graphs will show the degree of improvement the new highways will produce. - 102 - - - ~ --- Figure 44 PEAK-Hour PASSENGER CAR TRAVEL TIME BETWEEN CBD & ZONE CENTROIDS (we EKDAY-1970) OMAHA TRAFFIC STUDIES O 2 3. SCALE IN MILES WILBUR SMITH 8 ASSOCIATES Curves for the distribution of trips to and from places of work (Figure 35), non-work trips (Figure 36), residential truck trips (Figure 38) and industrial truck trips (Figure 39), may all be applied to the particular class of trips each was tailored to describe. The trip distributions which result from application of these curves represent a "first approximation” of the interchange of trips between zones. Two separate esti- mates for each infra-zonal movement are obtained. The two estimates are seldom in exact agreement because the element of competition between zones has not yet been accounted for. The theoretical pattern of trip distribution described by the curves represents an ideal condition. However, some zones must compete with many neighbors for an oppor- tunity to share trip-ends with zones which generate large volumes of trips. On the other hand, a peripheral zone may find little competition for trip interchange with its neighbors. Fratar has developed a method of “successive approximations” by which these competitive forces are averaged. The two sets of ‘‘first approximation” data derived in the manner described above have been subject to several cycles of Fratar's successive approximation technique in order to develop average estimates of infra-zone movements from the trip data in each zone. Resulting estimates of internal trip pro- jections for 1960 and 1970 are contained in Appendices Q and R (Person Trips) and Appendices S and T (Truck Trips). It should be noted that the accummulated total of trip as signments to and from each zone does not always add to the zone volumes from which projections were made. Discrepancies are generally within five per cent, however. A series of desire-line charts have been prepared to illustrate projected travel patterns in the Omaha Area for the year 1970. Figure 45 shows the 1970 estimate of auto driver trips between the CBD and the internal zones of the 1955 study. This drawing is comparable to Figure 24 for 1955 except for the external trip data which were included in that drawing. Figure 46 illustrates the probable pattern of transit travel to and from the CBD in 1970. The pattern of movement is very similar to that shown in Figure 26 for 1955. The volume of movement is only slightly greater. 1. ſº e © y 9 gº Frator, Thomas J. ‘‘Vehicular Trip Distribution by Successive Approximations", Traffic Quarterly, Volume VIII, Number 1, January 1954. - 104 - º ºver |4 - - - - . |- al-º-º- - - TRAFF-C. --- --- --- 24 Hºus wer - *** ** tº sº *Tº sº. - - * -- - Figure 45 AUTO DRIVER TRIPS TO AND FROM CENTRAL BUSINESS DISTRICT 1970 OMAHA TRAFFIC STUDIES --- O | 2 3. SCALE IN MILES WILBUR SMITH 8 ASSOCATES figure 47 illustrates the pattern of auto driver trips between all internal zones except the CBD and is comparable to Figure 25. Figure 48 shows the pattern of transit trips which can be expected in the Omaha Area by 1970. Service has been extended to a few zones where large population in- creases warrant. This drawing is directly comparable with Figure 27 for 1955. Figure 49 presents the pattern of internal truck movements for 1970, including travel generated by the CBD. This drawing may be compared with Figure 28 represent- ing 1955 travel. External trip data have not been included in the 1970 drawing, but the internal area of coverage is identical. External Area — The area of detailed trip projections for 1960 and 1970 has been extended to include the three-county Standard Metropolitan Area as described earlier. This was done to include new growth which is expected to occur before 1970 in areas beyond the 1955 cordon. Extension of the study area has led to development of detailed trip-desire in- formation over a much wider radius from Central Omaha. This is especially important in the low a portions of the Metropolitan Area. The 1955 origin-destination study provided detailed information at the Missouri River Bridges, but the traffic complex east of the River was not described. Travel with in Council Bluffs and its suburbs inevitably affects traffic approaching Omaha. The patterns of this travel which have been developed from trip characteristics developed from Omaha data are an approximation of these movements. Besides giving direction to Local movements just beyond the 1955 cordon, the analysis of external trips is greatly simplified by reducing the over-all volume of cordon traffic (traffic crossing the Standard Metropolitan Area limits). Such reduction is de- sirable because it is difficult to predict travel induced between Omaha and external areas without deriving future population and ownership trends in each external sub- division. Such a task is impractical unless it is accomplished in very general terms. By removing external stations farther from the Omaha Metropolitan Area, the volumes of cordon traffic have been reduced and the effects of arbitrary growth applied to external areas have been minimized. Traffic intercepted at any point on a highway will be found to be most heavily representative of the population immediately adjacent to the point of interception. Here, as well as within urban areas, the volumes of local movement are directly proportional to the populations joined by the highway and are inversely related to the travel distances - 106 - Mºssour River TRAFFIC º ºcco º - - - 24 Hous wºrkº Less rºan so shown ". Figure 46 TRANSIT RIDERS TO AND FROM CENTRAL BUSINESS DISTRICT 1970 OMAHA TRAFFIC STUDIES - _ _ | - 2 = SCALE IN MILES WILBUR SMITH 8 ASSOCIATES Figure 47 AUTO DRIVER TRIPS BETWEEN INTERNAL ZONES EXCLUSIVE OF CENTRAL BUSINESS DISTRICT 1970 OMAHA TRAFFIC STUDIES O 2 SCALE IN MILES º Es Lºss tºol shown - WILBUR SMITH 8 ASSOCIATES Figure 48 TRANSIT RIDERS BETWEEN INTERNAL ZONES EXCLUSIVE OF CENTRAL BUSINESS DISTRICT 1970 OMAHA TRAFFIC STUDIES . O 2 3. SCALE IN MILES sº-ºwer 14 7 ſ. -g - - - --- -H tsasºic scale soºn- 4000- ----- - - º - | Avrº 24 Hous wºko º ----- * - note vºlumes Lessºn so WILEUR SMITH 8 ASSOCIATES between centers of movement in each population group. Thus, a good share of the ex- ternal travel intercepted at the county lines which represent the Standard Metropolitan Area limits is dissipated to destinations lying between the new external stations and the 1955 cord on line. External trips, as noted in Part IV, consist largely of traffic between the three- county Omaha Standard Metropolitan Area and other counties in Nebraska and low a. In developing probable future traffic volumes to and from outlying counties, the combined effects of three principal factors relating to traffic growth have been evaluated. These are the elements of population growth, increased auto ownership, and decreased travel time between Omaha and the counties as a result of highway improvement Population increases in the counties are expected to occur uniformly with over-all increases in the states. Vehicle registrations are already high in most rural counties and the rate of future increase is expected to be low. Trip length, (travel time) however, is expected to be materially shortened to most areas by over-all improve- ments to principal routes throughout the region served by Omaha. Route attraction will be greater for reasons other than travel time, of course, due to reduction of congestion and accident hazard. These considerations and other infangible benefits from highway development are expected to add up to very real improvements in the convenience of auto travel. Commercial travel will be affected in much the same way. Values have been ascribed to the three growth factors as follows: Table 12 Omaha Traffic Studies GROWTH FACTORS APPLIED TO PROJECTION OF EXTERNAL TRAVEL AT OMAHA STANDARD METROPOLITAN AREA LIMITS Quality Year Population Vehicle Ownership (Speed) of Travel 1955 100 100 100 1960 106 107 106 1970 120 | 22.5 | 20 - 1 10 - ºssour ºve- - TRAFFIc scale sºn- - 4000- good- º - - º _*** 24 Hour weekday ºves LEss-Trian ºn 24. - -º-, wo shºw | Figure 49 TRUCK TRIPS BETWEEN INTERNAL ZONES 1970 OMAHA TRAFFIC STUDIES O 2 3 SCALE IN MILES l WILBUR SMITH 8 ASSOCIATES Population in the counties is expected to increase some 20 per cent over 1955 population by 1970. The number of cars per 1,000 persons is expected to in- crease about 22.5 per cent by that date. Average speed of travel (over-all trip time) will increase as roads are improved and restrictions removed. An average improvement of 20 per cent is believed to be feasible (equivalent to increase in average trip speed from 50 mph to 60 mph). Trip Volumes at External Cordon – 1955 traffic volumes at the limits of the three-county Omaha Standard Metropolitan Area have been estimated from the most recent traffic census made by the highway departments of Nebraska and low a. These estimates do not include all the minor roads which cross the three-county boundary but do provide a reasonable evaluation of total volumes. Ten principal highways radiate from the Omaha Area and cordon volumes for minor highways have been grouped with the main highway nearest them to produce traffic estimates for ten principal “sectors” of traffic move- ment. Each sector serves a distinct portion of f he peripheral area and there is virtually no parallel traffic movement to be accounted for between adjoining segments. t The highway locations which constitute the “external sectors’’ for the 1960 and 1970 studies are described in Table 13 which shows estimates of station traffic volumes for 1955, 1960, and 1970. The combined effect of the three variables applied to traffic increase is expected to result in a 25 per cent increase in external traffic vol- umes over the 1955 estimate by 1960. By 1970 external auto traffic will be nearly double the 1955 volume, while truck travel is expected to increase by two-thirds in that time. Internal Distribution of External Trips – With the exception of CBD travel, trips at the external cordon have been distributed to internal zones according to the formula illustrated in Figure 42. The labor force and employment populations in each internal zone have been combined and grouped by increments of peak-hour auto travel time from each of the ten station groups, and the curves in Figure 42 applied. A rela- tive pattern of trip distribution has thus been obtained for autos and trucks passing each station group. These relative distributions have then been related to estimates of trip volume at each station and the trips generated in each zone determined. It is estimated that approximately 60 per cent of the external trips are generated by persons who live in Omaha. These trips are included in the estimates of trips made by residents of the city. Internal trip volumes were adjusted to exclude this external travel before making the internal trip assignments described earlier. - 1 12 - Table 13 Omaha Traffic Studies EST IMATED TRAFFIC VOLUMES AT EXTERNAL STATION GROUPS A T OMAHA STANDARD METROPOLITAN AREA LIMITS Location of Stations Estimated Volume Through Station Group Station 1955 1960 1970 Group Route Auto Truck Tofal Auto Truck Total Auto Truck Total A U. S. 73 N. of Omaha 1,935 515 2,450 2,420 645 3,065 3,790 855 4,645 B U. S. 275 W. of Omaha 3,500 935 4,935 4,375 l, 170 5,545 6,860 1,550 8,410 C U. S. Alt. 30 - at Platte Road 1,970 530 2,600 2,465 660 3, 125 3,860 880 4,740 D U. S. 6 at Platte Road 4,560 1,040 4,700 5,700 1,300 7,000 8,940 1,725 10,665 E U. S. 75 at Platte Road 4,490 1,210 5,700 5,610 1,515 7, 125 8,800 2,010 10,810 F U. S. 275 South of Council Bluffs 3,065 815 3,880 3,830 1,020 4,850 6,005 1,355 7,360 G U. S. 59 @ Mills County Line 590 160 750 735 200 935 l, 155 265 1,420 H U. S. 6 East of Council Bluffs 2,785 825 3,61 0 3,480 1,030 4,510 5,465 1,370 6,835 | U. S. 59 @ Shelby County Line 1,700 450 2, 150 2, 120 560 2,680 3,330 745 4,075 J U. S. 75 and 30 Alt. North of Council Bluffs 2,030 620 2,650 2,545 775 3,320 3,980 1,030 5,010 Total Volume 26,625 7,100 33,725 33,280 8,875 42,155 52, 185 l 1,785 63,970 Index (1955 = 100) 100 I00 I00 125 | 25 125 196 l66 190 A rather large proportion of external trips are generated in the CBD. About 10 percent of external auto traffic and 8 percent of external trucks have been assigned to zones 00 and 01. The remaining trips were distributed to non-CBD zones as described above. - 1 13 - The origin-destination tables for external trip as signments are included in Appendices U, V, W and X. Data from the external trip analyses have been plotted on three drawings to illustrate the patterns of external movements. Figure 50 shows the pattern of trip movements to and from the CBD. In addition to travel between the CBD and external stations, the travel from zones outside the CBD cordon has also been plotted. Figure 51 demonstrates the movement of auto travel from external stations and peripheral zones within the Standard Metropolitan Area to non-CBD generators within the 1955 cordon. Zones within the City of Omaha have been grouped to simplify the presentation of data. Figure 52 shows truck travel from station groups and peripheral zones to zone groups within the 1955 cordon. - l l 4 - º ºr soundan, *** -ou-pany Doo *act musen toº mu-ºn *** *Dºº 70s |28 713 |23 --- [] ------- -------- *D --- 72 - ------- *C. rºe-on --- Dº *Eſ --------- Figure so AUTo DRIVER TRIPs EXTERNAL STATIONS AND TRAFFIC scALE 5000 PERIPHERAL zoNEs. To AND FROM - CENTRAL BUSINESS DISTRICT Avºgt 24 *Quº weekday 1970 Nº LE "...". Than so OMAHA TRAFFIC STUDIES o T. º ---. SCALE IN MILES WILBUR SMITH & Associates *[]* AUTO DRIVER TRIPs EXTERNAL STATIONS AND PERIPHERAL ZONES TO AND FROM - TRAFFIC SCALE INTERNAL ZONES ... EXCLUSIVE OF 2000- CENTRAL BUSINESS DISTRICT O avºnast 24 Hour weekDAY 1970 Note volumes LEss THAN 60 OMAHA TRAFFIC STUDIES NOT shown *- O 2 4. 5 e IO - T-T -ºu-D- - - - - ------- OOO Ract Mu-ee- OOO wome ºuwers --------- ------- *Loo --- **t --------- Figure 51 SCALE IN MILES WILBUR SMITH 8 ASSOCIATES - - - - - - - m = m. m. m = m. m. m. m. m. m. *\\levelº - - ºut----- - ---- ºut-º-º- OOC TR-T -u-º-º: OOO -o-º: Nu-º-º: | 24 *Dºwntº ------- underwood --- º 552. 7-12 UA-A*- ºtſ Macrºn- 688 --- D ---|--|--|-- ser |O9 Figure 52 TRUCK DRIVER TRIPS EXTERNAL STATIONS AND TRAFFIC SCALE PERIPHERAL ZONES TO AND FROM - - INTERNAL ZONES 2 º' - o AVERAGE 24 Houº WEEKony 1970 NOTE: volu-Es Ess THAN ed OMAHA TRAFFIC STUDIES NOT snown ------- o 2 4. e 3. lº, SCALE IN MILES WILBUR SMITH 5, ASSOCIATES \ ） → → → → → • • • • • *） DATE DUE