Integrated model for lane-use and signal-phase designs

The development of a codable model for the design of lane-use and signal-phase control at isolated intersections is valuable especially in developing countries where experienced traffic engineers are scarce. Extensive research concerning the design of signal phases and timing have been conducted in the past while very little has been done for the optimal design of the lane-use or lane-configuration of intersection approaches. However, poor matching of lane-use design and signal-phase design also produces a poor overall result. It is therefore necessary to integrate the design of lane uses and signal phases, and perform the optimization simultaneously. A mixed integer linear programming model is introduced for this purpose. The resultant designs are verified by comparing their performance indices with that of the existing designs as computed by TRANSYT-7F. The traffic data used are collected from a selected area of Shenzhen, one of the largest special economic zones of the People's Republic of China. The results indicate significant improvement in minimizing overall delay, stop, and fuel consumption.