考虑拖延行为的排队长度模型研究

HCM2000 Back of Queue模型(BQ模型)的计算值比实际调查值偏大,而且模型关于排队车辆的界定不能保证现场调查的客观性。提出了车辆拖延行为的定义,分析了拖延行为使BQ模型偏大的2种情况。建立了拖延行为模型,将车辆减速-停车等待-加速过程转化为温和减速-低匀速-温和加速的3阶段模型。通过低匀速行驶时间与停车时间之间的关系,可以得到车辆发生拖延行为的条件。建立了考虑拖延行为的排队长度与BQ模型之间的关系,并以首辆拖延车辆能否通过交叉口以及饱和度是否大于1为判别条件,提出了排队长度修正模型。通过实例验证了修正模型的可行性,而且修正模型可以保证现场调查的客观性和可操作性。

Back of Queue Model Based on Dragging Behavior of Vehicles

A major improvement in HCM 2000 is the introduction of Back of Queue model(BQ model) for signalized intersection.However,estimation values by BQ model are larger than survey values;and the judgments about queued vehicles would be invalid comparing to field survey.The definition of dragging behavior of vehicles was given.The reasons for overestimation of BQ models were analyzed and could be classified into 2 cases.The dragging behavior model was presented in which the deceleration-wait-acceleration process was transformed into mild deceleration-slow driving-mild acceleration process.The occurrence condition for dragging behavior could be obtained according to the relationship between slow driving time and waiting time.The revised BQ model was proposed under 3 conditions about if the first dragging vehicle could pass the intersection and if the saturation degree is larger than 1.0.An example was given to indicate the applicability of the revised BQ model and its benefits to field surveys.