文章编号： 1672-5328（2016）06-0067-08

赵巍，徐汉清
(天津市市政工程设计研究院，天津300051)

摘要： 长周期和倒计时是中国相对于发达国家城市道路交叉口信号控制方案的两个独有特征。基于 实证数据分析两类信号控制特征对车辆排队消散特性的影响。共观测天津市两处典型的长周期倒计 时信号控制交叉口的7 条直行车道。实证数据表明，中国城市道路交叉口长周期倒计时信号控制下 的排队消散过程大致可分为3 个阶段：启动阶段、稳定阶段和上升阶段。通过有序样品聚类的方法 确定3 个阶段的分割点。这与HCM 2010 等经典理论假设的排队消散特性明显不同，因此分析传统 通行能力估计算法HCM 2010 的适用性，并提出简单线性法、抛物线法和两段线法3 种通行能力估 计方法以减少传统方法估计中的误差。通过比较发现，抛物线与两段线拟合方法对通行能力的估计 较为准确，均方根误差( RMSE )均小于30 pcu·h-1。

关键词： 城市交通；信号控制；排队消散特性；通行能力；有序样品聚类；长周期；倒计时

中图分类号： U491.2+6

文献标识码：A

Impacts of Signal with Long Cycle and Duration Countdown on Queue Discharge at Signalized Intersections

ZhaoWei, Xu Hanqing
(Tianjin Municipal Engineering Design & Research Institute, Tianjin 300051, China)

Abstract： Long cycle and duration countdown are two unique characteristics of signalized intersections in China by comparison to those developed countries. This paper empirically investigates the impacts of such two characteristics on queue discharge at signalized intersections. For this purpose, seven traffic lanes at two typical intersections with long cycle and duration countdown are selected as study sites in Tianjin. The results show that the discharge process of queuing vehicles can be divided into three stages: start-up stage, stable stage, and rising stage. The ordered samples clustering method is used to identify the three partitions in which the findings are distinguished from the conventional assumption of capacity estimation methodologies, namely HCM 2010, the adaptiveness of traditional methods are thus analyzed. Furthermore, Piece- Wise Linear Method, Quadratic Linear Method, and Simple Linear Method are proposed to implement a better capacity estimation. The comparison results suggest a relatively more precise solutions from Piece- Wise Linear Method and Quadratic Linear Method where the RMSE is less than 30 pcu/h.

Keywords： urban transportation; signal control; queue discharge characteristics; capacity; ordered samples clustering; long cycle; duration countdown