The Effects of Simplifying Traffic-Zone and Street-Network Systems on the Accuracy of Traffic Assignments in Small Urban Areas in Indiana

摘要

As a part of a detailed study of synthetic travel demand modelling techniques that can be applied to small urban areas (population 50,000 to 250,000), this study concentrated solely on the traffic assignment phase of the modelling process. The study considered the effects of the following factors on the accuracy of traffic assignment: number of traffic zones, use of census tracts as traffic zones, complexity of the network configuration and method of traffic assignment. Transportation network and travel data from two small Indiana urban areas, Lafayette and Anderson, were used. The results indicated that traffic zones, based upon census tract boundaries, and street networks with less detail, can be used without significant reduction in assignment accuracy. For the small urban areas considered in the study 90 internal zones can provide acceptable accuracy in traffic assignment.