Traffic forecasting for project development

The traditional modeling process was developed in response to the need to evaluate future transportation needs in large, rapidly growing urban areas. The process is an excellent tool for evaluation of land-use/transportation alternatives. However, it is generally recognized that such a system level must be refined for project-level applications. A case study showed that the manual procedure followed by the Texas Corridor Analysis Group produced results which were different from the traffic assignments results using the TRANPLAN micro-computer package. A new alternative procedure for performing corridor analysis is proposed. This procedure is illustrated through a case study. A capacity restraint procedure which equalizes the V/C ratio of groups of links which constitute competing routes was developed and tested. The prototype model demonstrated that the V/C ratios of the links in each group converge toward the average V/C for that group. Counted volumes for turning movements were not available. Therefore, the assigned turning movements utilizing the equalized link V/C ratio method were compared to the results using the incremental capacity restraint procedure. The equalized link V/C procedure was judged to produce turning movements which are more realistic than the present capacity restraint method (A).