Citation

Clark J. ITE J. 2008; 78(8): 24-29.

Copyright

(Copyright © 2008, Institute of Transportation Engineers)

DOI

unavailable

PMID

unavailable

Abstract

Current analytical methods for signal timing split optimization can be categorized into two forms: (1) volume-to-capacity (V/C) methods, based on balancing some form of critical movement V/C to provide an approximate minimization of total intersection delay; and (2) movement delay methods based on evaluation of an individual movement's delays, usually focused on balancing or minimizing critical movement delays. This paper assesses these traffic signal timing split optimization methods and the problems associated with them. The methods are compared using a simple signal timing experiment. The findings suggest that the traditional V/C methods produce a significantly disproportionate share of delay among the critical movements compared to movement delay methods. This indicates that the traditional V/C methods used to determine optimum splits result in the major high-volume critical movements enjoying low delays at the expense of the low-volume critical movements. Rather than using V/C as an objective function for determining optimum splits, signal timing split optimization should be based upon individual critical movement delays to achieve sensible signal timings for all movements.