On the performance of adaptive traffic signal control.

ABSTRACTIn this paper, we present a study in understanding sensing error's impact on traffic signal control performance. Adaptive traffic signal control systems depend on information from traffic sensors to interpret the state of traffic. Signal timings are adjusted at real time according to the state of traffic. Queue length is an important element of the state of traffic, and errors in estimating queue length influences control decision and hence the performance. This paper presents the first attempt to quantify the effects of sensing error on control performance in the field of traffic control. A novel technique to estimate queue length using data from single loop detector is presented, and estimations are compared with parallel observations. The results show that moderate overestimation of queue length may significantly improve control performance. The benefit from overestimation suggests including arriving traffic in system state, and using look-ahead algorithms to calculate signal timings.