Feasibility Assessment for Implementing Adaptive Traffic Signal Control

Abstract

Adaptive traffic control systems (ATCS) continuously adapt to changing traffic in order to improve traffic performance at signalized intersections. Typical before–after studies evaluate the success of ATCS deployments by assessing only the postimplementation traffic performance. Fully assessing the feasibility of ATCS implementation, however, requires evaluating the changes in long-term ATCS performance with changing traffic demands. This paper illustrates the assessment of long-term ATCS performance of two study corridors. The study uses volume/capacity (v/c) ratio to evaluate the effects of changing corridor flow on corridor-wide delay benefits. The results show that the Sydney Coordinated Adaptive Traffic System (SCATS) improves corridor flow and decreases corridor-wide delays up to a point of ineffectiveness, beyond which the ATCS performance begins to decrease. The ineffectiveness point helps in deriving a reasonable estimate for the magnitude and duration of potential ATCS deployment benefits.