Traffic Signal Timing Models for Oversaturated Signalized Interchanges. (InterimReport March 1989-January 1992)

摘要

The research report documents the development models for control of signalizeddiamond interchanges during oversaturated traffic conditions. Oversaturated traffic conditions occur when the average traffic demand exceeds the capacity of the signal system. The dynamic optimization model proposed is the principal product of the research. The control objective of the dynamic model is to provide maximum system productivity as well as minimum delay for a selected roadway system. A special feature predetermined upper limits. The dynamic model was developed for conventional diamond interchanges and three-level diamond interchanges. The model takes the form of mixed integer linear programming. The effectiveness of the control strategies generated by the dynamic model was compared to those derived from conventional signal timing models, using the TRAF-NETSIM microscopic simulation model. It was found that the dynamic models produced optimal signal timing plans for the oversaturated signalized interchanges. The dynamic model consistently outperformed conventional models with respect to system productivity. The conclusion was drawn from the TRAF-NETSIM simulation. The dynamic model solutions significantly reduced total system delay for most test cases, while slightly increasing the delay for a few test cases.