To improve signal timing and traffic flow operation at the intersection with contraflow left-turn lane, the application condition for the contraflow left-turn lane was developed. The arrival and discharge pattern of left-turn vehicles were divided into 8 groups and the calculation method for left-turn vehicle delay under each group was carried out. The average intersection vehicle delay minimum was taken as the objective, cycle length, green times of main and pre-signal phases, and the lengths of contraflow left-turn lanes were taken as optimization variables, and then the signal control plan optimization model was developed. The genetic algorithm was used to solve this model. A case study was conducted to validate the optimization method, which was also compared with the traditional control method. Results show that the optimization method can increase the capacity of left-turn vehicles, decrease the required green time and then reduce the intersection cycle length. The decrease in the green time of left-turn phases would result in the decrease in the red time of through phases and then the decrease in intersection average delay. In peak hour, average vehicle delay can be decreased by 23.8%.%为提高借对向出口车道左转交叉口信号配时的科学性以及交通流运行效率,提出借对向车道左转的适用条件,将左转机动车的到达-驶离图式分为8种情况,分别建立每种情况下左转机动车的延误计算方法.以交叉口车均延误最小为目标,以周期时长、主信号与预信号各相位绿灯时间、借对向车道左转车道的长度为优化变量,建立了交叉口信号控制方案优化模型,并采用遗传算法进行求解.以算例的形式对所建立的优化方法进行验证,并与传统控制方法进行对比.结果表明:优化方法可以提高左转机动车通行能力,减少其所需绿灯时间,进而缩短交叉口周期时长;左转相位绿灯时间的缩短减小了直行相位的红灯时间,进而缩短了交叉口的车均延误,在高峰期交叉口车均延误下降比例达到23.8%.
展开▼
