基于虚坡模型的交叉口交通流的解耦方法

Imaginary Slop Model Based Decoupling Method Proposed for Crossing Traffic Flows

交叉口交通流的模型是进行红绿灯优化管理仿真模拟的基础。传统的方法仍有其不足之处,主要表现在对统计手段有较大的依赖性。为此,提出了一种基于虚坡模型的解耦方法,它将路口的红灯黄灯效应用假想路障代替,将一个方向上的车流对另一个方向上车流的影响用另一个假想的宽度变化的路障代替,而假想路障则在虚坡模型中表示为速度为零的车辆。由此,交叉口两个方向上的交通流被表示为两条独立道路上的交通流,用虚坡模型算出每一方向上各车的行驶规律,并求出折合行驶延误时间。调整信号灯切换时间令总体延误时间为最小,就能得到最佳的信号灯管理方案。通过对一个大规模问题的试算,得到了有用的结果,表明可用虚坡模型通过仿真手段对交通管理问题进行直接研究。

The calculation of crossing traffic flows is a basic problem in the simulation of traffic light （signal light） management. The traditional methods still have their shortcomings. One of them is that they depend on statistical methodologies to a great extent. Based on the imaginary/virtual slop model, a decoupling method for crossing traffic flows was proposed. It used an imaginary road block to simulate the effect caused by the red lights and the yellow lights. And another imagined road block was introduced to express the effect of the traffic flow in one direction on the traffic flow in another direction. The width of the latter was thought to be changing. Both of the two imaginary road blocks were expressed as additional imaginary vehicles of zero speeds. And the calculation of the two crossing traffic flows was decoupled to the calculation of two independent traffic flows. Further the imaginary slop model was applied to determine the running process of the vehicles. In this way the total delayed time of all vehicles was found. Regulating the on-off time of the traffic lights to minimize the total delayed time of the vehicles, an opti mal management arrangement of the traffic lights was found. The proposed method was applied to a problem of large scale and useful results were produced. It showed that traffic management problems could be simulated directly with the imaginary slop model.