A Capacity Model of Signal-Controlled Road Network Considering Delay of Intersections

Abstract

The capacity of a signal-controlled road network is a problem of finding the optimal design parameters while taking into account the route choice of users. Conventionally, the study focused on splits (proportions of green times), which can adjust the capacity of entries of intersections, thus influencing the capacity of road networks. But actually, signal-timing can also influence capacity of road networks by changing delay of entries of intersections. Because the delay of intersection is an important part of travel time, which can influence the route choice of users. Based on this, a bilevel programming model is proposed. The lower-level problem represents a network equilibrium model involving delay of intersections, which predicts how drivers will react to any given signal control pattern. The upper-level problem is to determine signal parameters to maximize capacity of road networks, taking account of driver' route choice behavior in response to signal timings. The optimizing parameters are cycle times and splits. A heuristic solution algorithm based on sensitivity analysis is proposed to solve this problem. The application of the model and its algorithm is illustrated with a numerical example. It is worth mentioning that the authors get a larger capacity taking account of delay of intersections.