平面信号交叉口通行能力停止线计算法的改进

Improvement in Stop Line Method for Calculating Capacity of Signalized Plane Intersection

为了更加合理地计算平面信号交叉口通行能力,对停止线法的计算公式进行改进。对停止线法进行合理性分析,发现在计算专用左转车道和专用右转车道通行能力时,停止线法受到各车道饱和度之间关系的限制,而其他类型车道的通行能力计算公式没有这种局限性。在挖掘信号配时、车头时距等通行能力影响因素的基础上,类比直行车道通行能力计算方法,重新构造专用左、右转车道通行能力计算公式,标定其中的折减系数以及相关变量的参考值,并对各类型车道通行能力计算公式进行整合,得到改进的停止线法。通过案例分析,比较现有方法和改进方法的实施效果,结果表明:改进方法能够弥补现有停止线法的上述不足之处。

In order to calculate capacity of signalized plane intersection more reasonably,it is necessary to improve formulas in stop line method.First,stop line method is analyzed in the aspect of reasonability.It has been found out that formulas in stop line method,which calculate capacity of special left-turn or right-turn lanes,are limited by relationships among saturation degrees of all the lanes,while calculation formulas of the other kinds of lanes＇ capacity do not have such limitation.Then,such influencing factors of capacity such as signal phase and time headway are excavated.With calculation method of straight lane capacity as analogy,the capacity calculation formulas of special left-turn or right-turn lane are established afresh.The deduction coefficients as well as relevant variables are determined.Moreover,the capacity calculation formulas of all kinds of lanes are integrated.As a result,an improved stop line method is obtained.At last,the effects of existing and improved methods are compared through case analysis.The results show that improved method can make up the imperfection of existing stop line method.