考虑右转车流的交叉口交通岛比选设计

摘要

交通岛设计的关键是确定右转车流在进口道分流区及出口道合流区的交通组织，在此基础上进行方案设计和通行能力评价。目前的设计缺乏对在不同右转流量条件下方案优化和比选时的定量化分析。本文提出右转车流在不同交通组织条件下的四种交通岛设计方案，并采用通行能力模型对进口道分流区及出口道合流区通行能力进行评价，提供不同右转车流需求下的交通岛最佳设计方案。算例结果表明：随着右转车流量的变化，本文提出的四种交通设计方案与右转车流的四个流量区间一一对应，能够满足复杂条件下的城市交通精细化设计需求，解决了目前设计单一化、非定量化的弊端。%The keys of traffic island design are to determine the different traffic organizations for right turn traffic flow in the entrance lane diverging and exit lane merging areas and to accomplish the scheme design and lane capacity evaluation. The current design lacks consideration of the scheme optimization and quantitative analysis when comparing and selecting the designs under the condition of different right turn traffic flows. Condidering right turn traffic flow, four schemes of traffic island design were proposed in the circumstances of different traffic organizations for right turn vehicles. Moreover, the lane capacity of the entrance diverging and exit merging areas could be evaluated by using the lane capacity model and then the optimal design of the traffic island was obtained after comparing the calculated capacities under different right turn traffic flows. The result shows that: there is a one-to-one correspondence between the four traffic island design schemes and the four right turn traffic volume intervals change with the right turn traffic volumes, which can meet the need of the precise design of urban traffic under complicated conditions and make up the drawbacks of simplification, non-quantification in the current design ways.