Modeling of Signal Cycle for Transit Priority

Giving priority to transit vehicles at urban intersections could improve transit operation and schedule reliability and attract ridership, it may also be an effective way to alleviate traffic congestion. This paper reports a new method to compute the cycle length at signalized intersections based on the principle of people oriented transportation systems. This is a departure from the current signal timing mechanism based on the average delay per vehicle, which is naturally in favor of private vehicles. Taking the minimum delay per person as the objective and based on the linear programming planning, the author developed a model calculating the optimal cycle length. Furthermore, the model was calibrated and validated in a case study. The result shows that, comparing with traditional control program, the model not only reduced delay per person but also diminished the delay per car dramatically at the same time. It demonstrated that giving priority to bus not only improve bus services but also improve all traffic at urban intersections.