两相位交叉口左转交通流冲突延误改进模型

Improved left-turn conflict delay model at two-phase intersection

为改善两相位交叉口左转车流与直行车流冲突延误模型的适应性,解决现有冲突延误模型多以负指数分布为主描述车头时距分布与信号控制交叉口的实际运行状态不一致问题,用M3车头时距分布对冲突延误模型进行研究.首先采用M3分布来描述交叉口车头时距分布,并考虑左转车排队延误以及1个周期内绿初直行车排队数对冲突延误的影响,建立两相位交叉口冲突延误改进模型.结果表明:改进后的冲突延误模型计算得到的左转车在冲突点处的延误与实际比较吻合,从而模型的有效性得到验证.模型既完善了现有冲突延误的计算理论,又可以为信号配时进一步优化提供理论依据。

To improve the applicability of the conflict delay model between left-turn vehicle and straight vehicle in the opposite direction at two-phase intersection,the conflict delay was studied on the basis of M3 distribution.M3 distribution of time headway for straight vehicle is more suitable than negative exponent distribution at signalized intersection.The queue delay of left-turn vehicle and the affect of the number of straight queue vehicles on conflict delay at the beginning of green were considered when M3 distribution was used in this paper.Then a new conflict delay model at two-phase intersection was put forward and it proved effective.The result shows that the conflict delay model improved closely meets with reality and it proved effective.It consummates the theory of existing conflict delay calculation and can provide the theoretical basis for setting up signal phases further.