ENHANCEMENTS TO THE PASSER II-90 DELAY ESTIMATION PROCEDURES

An enhanced delay estimation model for the popular traffic signal optimization model PASSER II-90 is described. Although the results from this model focus on enhancements to PASSER II-90, the findings presented should be useful to the future formulation of the "Highway Capacity Manual" (HCM) methodology for arterial streets. Development of the enhanced delay model primarily involved a four-step arrival rate model instead of the current two-step arrival rate model. Total delay was calculated on the basis of whether the traffic arrivals were early or late. Specifically, delay was estimated using the length and the time of arrival of the traffic platoon at the downstream intersection. TRANSYT-7F was used to investigate the effectiveness of the current PASSER II model and the enhanced PASSER II model. The enhanced PASSER II delay model resulted in large reductions in deviations of the delay values from TRANSYT-7F. Delay-offset trends in enhanced PASSER II-90 now closely follow the TRANSYT-7F delay-offset curves. Delays were also observed to closely follow the NETSIM curves in some regions. It was also observed that in the optimization mode, there was no significant difference in the calculated delay values between the old and the new estimation models. The new delay estimation model in PASSER II-90 also demonstrated that the platoon dispersion modeling in PASSER II compares favorably with TRANSYT's platoon dispersion factor of 0.30 to 0.35. Conclusively, the new model in PASSER II-90 has substantially improved delay estimation over all possible offsets for through traffic.

Language

  • English

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 94-103
  • Monograph Title: Traffic control devices, visibility, and traffic signal systems
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00647272
  • Record Type: Publication
  • ISBN: 0309055741
  • Files: TRIS, TRB
  • Created Date: May 2 1994 12:00AM