Optimization of two-way traffic signal timing control

A new method of two-way traffic signal timing control based on speed is presented. The whole control structure is divided into the decision-making level and control level. Two new measurements are put forward which weigh traffic urgency degree and differentiate traffic flow states separately based on traffic demands. Two-way traffic control and one-way traffic control can be transformed into each other according to the urgency degree. Taking speed as a measure is based on the fact that the road section distance and intersection conditions are changeless and they are out of control. Such classical direction coordinated control strategy as synchronous and asynchronous coordinated control are impractical because of their limited use, that is, they require equal section lengths on arterials. The algorithm is based on our proposed one-way control method which changes the control aim timely depended on the vehicle queue length variation during the adjacent cycle and the relationship between the number of the arrival and departure vehicles in the same cycle. The experimental results demonstrate the method's ability to realize the running of the two-way traffic and indicate that the proposed discrete type performance index model is a more appropriate design for two-way traffic signal timing control.