Citation

Chan Y, Liao T. ITE J. 1987; 57(2): 45-50.

Copyright

(Copyright © 1987, Institute of Transportation Engineers)

DOI

unavailable

PMID

unavailable

Abstract

This article discusses simulation and analysis of driver response to a yellow light, and describes a procedure that can be used to scientifically set change intervals at signalized intersections. The associated computer program is also described. The procedure was employed to analyze 18 yellow lights in a city in Washington State. The results show that most change intervals in the field are shorter than desired as indicated by the existence of dilemma zones. Case studies show that there are a number of ways to eliminate the dilemma zone in the field. Apart from the obvious option of altering the change interval, it was found that adjustment of speed, repaving roads, and cutting down cross-street width through improved markings are equally viable. An interesting adjustment is the revision of the speed limit upward to minimize the dilemma zone.