00311232

Component

http://onlinepubs.trb.org...ubs/sr/sr187/sr187-030.pdf

Although various validation studies have shown that synthetic urban-transportation-study techniques can achieve acceptable results when compared with conventional traffic assignments and ground counts, two questions have been frequently raised: does this favorable comparison indicate that the trip matrix developed by synthetic procedures reflects actual travel patterns?, and how sensitive is the assignment to the input data? This paper discusses a sensitivity analysis that used data from an urban transportation study in Tyler, Texas to help answer those questions. Four matrices were assigned to the same network and compared--the first three of which were assignment matrices and the last being the existing trip matrix: a stochastic trip matrix constrained only to the number of trips in the study area; a stochastic trip matrix constrained only to the number of trips in the study area; a stochastic trip matrix constrained to total trips, trip-length frequency, and trip ends at each external station; and the fully modeled trip matrix. Analysis of the results from the assignment indicates that, as long as an accurate trip-length frequency is used in generating the trip matrix, the assigned vehicle kilometers of travel will very closely match the counted vehicle kilometers of travel, even when the distribution of zonal trip ends is unrealistic. It was concluded that acceptable assignment results can be expected if the following conditions are satisfied: the correct mean trip length is used, the total number of trips in the study area is correct, and a reasonable approximation of the geographical distribution of trip ends is achieved.

This paper appeared in TRB Special Report 187, Transportation Planning for Small and Medium-Sized Communities, Proceedings of a Workshop sponsored by UMTA and FHWA, conducted by TRB, Sarasota, Florida, 3-6 December 1978. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved.

00311201

pp 78-79

1980

Transportation Research Board Special Report

Workshop on Transportation Planning for Small and Medium-Sized Communities

Digital/other

References (3) ; Tables (1)

Alternatives analysis; Analysis; Forecasting; Traffic; Traffic assignment; Traffic counting; Transportation planning; Travel patterns; Trip distribution; Trip length; Urban transportation; Vehicle miles of travel

Traffic analysis

Highways; Operations and Traffic Management; Planning and Forecasting; Public Transportation

TRIS, TRB, ATRI

Jul 22 1981 12:00AM

• A DIAGNOSTIC APPROACH TO MANAGEMENT INFORMATION SYSTEMS
• A SIMPLIFIED TECHNIQUE FOR TRANSPORTATION PLANNING
• A TRAFFIC ENGINEER'S PERSPECTIVE ON FEDERAL TRANSPORTATION FUNDING PROGRAMS FOR URBAN AREAS
• A VITAL PHASE OF TRANSIT EVOLUTION: MANAGEMENT INFORMATION SYSTEMS
• ACHIEVING A BALANCE BETWEEN LONG-RANGE AND SHORT-RANGE PLANNING AT AN APPROPRIATE LEVEL OF EFFORT
• APPLICATION OF MANUAL TECHNIQUES FOR TRAVEL-DEMAND ESTIMATION
• APPROPRIATE LEVEL OF EFFORT FOR PLANNING FOR SMALL AND MEDIUM-SIZED COMMUNITIES
• COMMERCIAL DATA SOURCES FOR TRANSPORTATION PLANNING
• DWELLING-UNIT TO PARKING-STALL TRIP-GENERATION ANALYSIS (ABRIDGMENT)
• ESTIMATING TRANSIT DEMAND, FLEET SIZE, AND COSTS FOR SMALL COMMUNITIES
• FORECASTING GROWTH PARAMETERS IN SMALLER URBAN AREAS
• FORECASTING TRANSIT RIDERSHIP IN SMALLER COMMUNITIES
• GEOGRAPHIC DATA RESOURCES FOR SMALL AND MEDIUM-SIZED URBAN TRANSPORTATION PLANNING PROGRAMS
• IMPLEMENTATION OF TRANSPORTATION PLANS
• INTRODUCTION AND CONFERENCE SUMMARY TO THE CONFERENCE PROCEEDINGS ON TRANSPORTATION PLANNING FOR SMALL AND MEDIUM-SIZED COMMUNITIES
• IOWA URBAN TRANSPORTATION AREA: TRAFFIC-COUNTING PROGRAM
• ISSUES AND LEVEL OF EFFORT
• ISSUES AND LEVELS OF EFFORT
• JOURNEY-TO-WORK DATA FROM THE 1980 CENSUS
• ORGANIZATION STRUCTURE FOR PLAN IMPLEMENTATION
• PLAN IMPLEMENTATION: TEXARKANA URBAN TRANSPORTATION STUDY
• PROCEDURE FOR ANALYSIS OF SYSTEM SUFFICIENCY AND DEFICIENCY (ABRIDGMENT)
• SIMPLIFIED PROCEDURE FOR ESTIMATING FUTURE TRIP GENERATION (ABRIDGMENT)
• SURVEILLANCE AND SOCIOECONOMIC FORECASTING
• SURVEILLANCE AND SOCIOECONOMIC FORECASTING
• SYNTHESIS OF HIGHWAY PLANNING AND IMPLEMENTATION IN URBAN AREAS OF ARKANSAS
• SYSTEM PLANNING
• SYSTEM PLANNING "DO'S AND DON'TS" FOR SMALL CITIES
• TECHNIQUES
• TECHNIQUES
• TECHNIQUES
• TRAFFIC ENGINEERING SERVICES FOR SMALL POLITICAL JURISDICTIONS
• TRAFFIC OPERATIONS AND PLANNING. ISSUES
• TRANSIT SERVICE STANDARDS, ROUTING, AND SCHEDULING
• TRANSPORTATION ACTION PROGRAM
• TRANSPORTATION AND TRANSIT PLANNING FOR SMALL AND MEDIUM-SIZED URBAN AREAS
• TRANSPORTATION PLANNERS AND LOCAL ELECTED DECISION MAKERS (ABRIDGMENT)
• TRANSPORTATION PLANNING IN SMALL AND MEDIUM-SIZED COMMUNITIES: GREATER FLEXIBILITY, IMPROVED COMMUNICATION, AND SIMPLIFIED REQUIREMENTS
• TYPES OF DATA THAT SHOULD BE MONITORED
• WHAT SHOULD WE BE TRYING TO DO IN THE TRANSPORTATION PLANNING PROCESS?