分离式与并行式双左转车道通行能力

Traffic capacity of the separate and the adjacent dual left-turn lanes

调查了分离式、并行式双左转内、外侧车道的饱和车头时距和饱和流率,并计算了2种双左转方式下,左转车道的饱和流率相对于相邻直行车道的饱和流率的折算系数,对分离式与并行式双左转车道通行能力进行了对比分析;调查了2种双左转类型下各左转车道高峰小时流量,计算高峰小时平均流量折算系数,通过折算系数的比较,明确不同左转类型下各车道交通流量的实际分担情况;最后对2种双左转形式的优缺点进行分析,为交叉口标志标线设计提供参考。研究结果表明:在左转绿信比相同的情况下,分离式双左转车道的通行能力略高于并行式。

The separate and the adjacent dual left-turn lanes' saturation headway and flow rates were investigated in the paper.At the same time,the conversion coefficients of left-turn lanes' s saturation flow rate relative to that of adjacent straight lanes were calculated under the two leftturn styles.And the traffic capacity of the separate dual left-turn lanes and the adjacent dual leftturn lanes was compared;The peak hour flow of the two left-turn lanes,types was investigated,and the convertion coefficients of the average peak hour flow were calculated.By comparing the conversion coefficients,each lane's actual traffic flow sharing situation was clear in the different types of left-turn.Finally,the advantages and disadvantages of the two types of dual left-turn lanes were analyzed,and the results could provide a reference for signs and markings design of intersection.The results show that the traffic capacity of the separate dual left-turn lanes is higher than that of the adjacent dual left-turn lanes under the situation of the same left-turn green ratio.6tabs,2figs,10 refs.