Project Title: Improvement To Signal Timing Software

Sponsor: Texas Department of Transportation

Principle Investigator: Nadeem Chaudhary

Research Staff:

TTI Project Number: 440202

Start Date: 9/1/01

End Date: 8/31/02

Abstract: A number of computer programs are available for use in arterial signal timing projects. These include both bandwidth-based models and delay-based models. Most of these models are either not applicable to congested situations or their use for such situations is not well understood. Furthermore, it is also well known in the research community that each of these model has inherent strengths and weaknesses. However, no guidelines are currently available to aid the engineers in selecting the appropriate program(s) for use in signal timing projects. In addition, PASSER II, the best program for generating bandwidth-based signal timings for arterials may become obsolete due to recent advancements/changes in operations systems for personal computers. This two-year project has two primary objectives. The first objective is to compare the three most popular signal timing optimization programs and to develop guidelines for selecting the proper program(s) for use in signal timin g projects. These programs are PASSER II, Synchro, and TRANSYT 7F. The second objective is to enhance PASSER II: (1) to handle congested traffic conditions and to explicitly account for secondary platoons to/from side-streets, and (2) by developing a new user interface for Windows operating systems.