交通控制中展宽段设计与信号配时的优化

Optimization of stretching-segment design and signal timing in traffic control

针对展宽段设计与信号配时之间互相影响和制约的问题,本文提出了优化配时依据和相位相序的解决方法.分析了展宽段设计与信号控制之间的内在联系;提出了交叉口无空间限制条件下展宽段的设计思想,既应满足信号控制需求又要保证排队车辆不发生溢出,且要尽量减少对对向出口道车辆通行的影响,基于此思想综合运用交通控制理论及交通流理论建立了展宽段长度的计算模型;当交叉口空间受限制时,针对直左车流间无相互干扰的情况,提出了以当量饱和流率作为信号配时依据的控制思路,而对于直左车流间存在相互干扰较严重的情况,提出了优化相位相序的控制策略,结合韦伯斯特理论建立了以延误最小为目标的非线性优化模型,并采用遗传算法求解相关参数.最后利用VISSIM仿真软件对提出的方法和模型进行了模拟验证.

To deal with the interaction between the stretching-segment design and signal timing,we optimize the timing warrants,the phase and the phase sequence.By the intrinsic link between the stretching-segment and the signal control,we design the stretching-segment without considering the constraint for intersection space.This design not only meets the requirements in signal control,but also ensures no overflow for the queue vehicles and minimal impact on the opposite exit-lane traffic.By using the traffic control theory and traffic flow theory,we build the computational model for the stretching-segment length.When the intersection space is constrained,the equivalent saturation flow rate is used as the warrant for the signal timing in the control strategy,if there is not interference between the straight traffic flow and the left-turn traffic flow.On the other hand,if serious interference exists between these two traffic flows,the control strategy is to optimize the phase and phase sequence.By this strategy,we build a nonlinear optimization model based on Webster theory to minimize the delay and use genetic algorithm for determining associated parameters.The proposed methods and models are simulated for validity by using the simulation software VISSIM.