为获得更好的单点固定信号配时方案,以交叉口通行能力最大和车辆平均延误最小为目标,以相位有效绿灯时间受限为约束条件,提出一种信号配时优化模型.使用大连市交通调查数据得到韦伯斯特配时方案和2种优化配时方案,采用交叉口通行能力、车均延误和饱和度评价了各种配时方案.利用VISSIM软件进行了交通模拟试验,采用累计通过车辆数、车均延误和平均排队长度对各种方案进行了交叉口评价.结果表明,所提出的配时优化模型优于韦伯斯特配时模型,而且其评价结果更能反映交叉口的实际服务水平.
To achieve better pretimed signal timing plans for isolated intersections, a signal timing optimization model was proposed by using the objectives of maximizing intersection capacity and minimizing vehicle average delay with the constraints of the phase effective green times. By using traffic survey data from Dalian city, the Webster timing and two optimization plans were obtained. All timing plans were evaluated by the indices of capacity, average delay and degree of saturation. Several experiments to simulate traffic flow operations were made by applying VISSIM software. Also, these simulation plans were evaluated by the indices of cumulative number and average delay of vehicles traversing the intersection, and average queue length. The results indicate that the given optimization model is better than the Webster timing model to obtain the ratio of maximum intersection capacity to average delay and its evaluation results can better reflect actual service level of intersections.