考虑礼让行人的信号交叉口配时优化方法

为提高机动车礼让行人背景下的人车通行效率，研究了基于叠加相位设计的信号交叉口配时优化方法。以西安市1个典型交叉口为例，分析机动车与过街行人冲突情况；在Webster配时模型的基础上，提出叠加相位设计与人车冲突时空分离策略相结合的信号配时优化方法，并给出行人信号早启时间、人车绿时分离设置阈值的计算方法；运用VISSIM仿真软件，对不同信号配时优化方案的效果进行验证。研究结果表明：与现状相比，所提出的配时优化方法可分别降低各类延误27.11%（车均）、22.41%（人均）、27.08%（车辆总计）、22.49%（行人总计）和26.15%（交叉口总计），减少各类污染物排放3.76%（VOC）、3.76%（CO）、3.76%（NO_x），并降低燃料消耗3.78%。该方法能有效改善信号交叉口的通行效率，缓解人车冲突。

A Timing Optimization Method for Signalized Intersections Considering the Courtesy Rules to Pedestrians

In order to improve the efficiency of signalized intersections under the consideration of the courtesy rules from vehicles to pedestrians, a timing optimization method based on superposition-phase is proposed. A typical intersection from Xi'an is taken as a case study. The conflicts between vehicles and pedestrians are analyzed. Based on Webster's timing model, a timing optimization model is developed, which combines superposition phase design and space-time separation strategy for reducing the conflicts between vehicles and pedestrians. In addition, the calculation methods for starting time of pedestrian phase and the threshold for adopting vehicle-pedestrian phase separation strategy are proposed. Then VISSIM simulation software is used to verify the effectiveness of the proposed signal timing optimization schemes. The simulation results show that compared to the current scheme, the scheme from the proposed timing optimization method can reduce the average vehicle delay, delay per capita, total vehicle delay, total pedestrian delay and total intersection delay by 27.11%, 22.41%, 27.08%, 22.49%, and 26.15%, respectively. In addition, it can also reduce the emissions of VOC, CO, NO_x, and fuel consumption by 3.76%, 3.76%, 3.76%, and 3.78%, respectively. The proposed method can effectively reduce the vehicle-pedestrian conflicts and improve the efficiency of traffic operation at signalized intersections.