路口拓宽条件下专用左转车道通行能力分析及设计方法研究

通过路口拓宽设置专用左转车道,是改善交叉口运行条件、提高交叉口通行能力的一种有效手段.笔者通过对双左转车道饱和流量数据的分析,提出了在设计和分析时,应对内、外侧左转车道分别进行的建议,并给出了左转车校正系数的建议值.拓宽车道宽度与饱和流量的实测数据进行回归分析,得出专用左转车道宽度与饱和流量的二项式关系模型,并依据此模型给出了宽度校正系数.采用概率与统计分析的方法,找出了拓宽车道长度、直行车比例和拓宽车道上平均车辆数的关系,并推导出拓宽车道长度与通行能力关系模型.

Analysis on Capacity of Exclusive Left-turn Lane and Study on Design Method of Widening Approach

Widening approach and setting up exclusive left-turn lane are an efficient measure to improve running condition and increase capacity of intersections.Through analyzing the saturation of double left-turn lane,it is suggested that inboard and outboard left-turn lane should be designed and analyzed respectively.And the suggestion value of left-turn modificatory coefficient is put forward.Regression is adopted to analyze the data of widened lane width and saturation.The binomial relationship model is established between the width and saturation of exclusive left-turn lane.And the width madificatory coefficient is given according to this model.Using the method of probability and statistic analysis,the relationship is found among the length of widened lane,the proportion of through vehicles and average number of vehicles on the widened lane.Finally,the relationship model is produced between the length of widened lane and capacity.