平行流交叉口左转非机动车钩形转弯优化设计

Optimization design for left-turn non-motor vehicle crossing at parallel flow intersection with hook-turn

摘要:

为提升平行流交叉口的运行效率,消除左转非机动车和直行机动车冲突,将钩形转弯的概念引入到平行流交叉口设计中,给出非机动车过街控制策略,并结合机动车通行和行人过街,将其整合到一个统一的优化模型中。考虑信号相位相序、绿灯时长、周期时长、左转非机动车待行区容量、非机动车清空时长、车道平衡等约束条件,以机动车通过量最大为优化目标,建立线性规划优化模型。研究结果表明:两步过街和优化设计解决了左转非机动车安全过街问题,是平行流交叉口非机动车过街设置的有效替代设计方案；在低高两种流量场景下,相对于常规设计,两步过街分别降低了35.02%、55.52%的机动车延误,优化设计分别降低了42.71%、65.60%的机动车延误；两步过街会造成左转非机动车延误大幅增加,不适用于左转非机动车流量较高的场景；常规设计机动车最大通过量受直行机动车流量和左转非机动车流量的影响最为严重,说明消除左转非机动车和直行机动车冲突,对提升交叉口通行能力作用显著,有助于推动绿色出行发展。

Abstract:

To boost the operational efficiency of parallel flow intersections and further eliminate the conflict between left-turn non-motor and straight-through motor vehicles, a control strategy for non-motor vehicle crossing was proposed and then integrated with motor vehicle crossing and pedestrian crossing into a unified optimization model. Considering the constraints such as signal phase sequence, green light timing, cycle length, capacity of the waiting area for leftk-turn non-motor vehicles, clearance time of non-motor vehicles, and lane balance, the linear programming optimization model was constructed so as to maximize traffic capacity. Results show that two-step street crossing and optimization design could both solve the crossing problem of left-turn non-motor vehicles, which are effective alternative design schemes for non-motor vehicle crossing at parallel flow intersections. Compared with conventional design, the two-step street crossing reduced the motor vehicle delay by 35.02% and 55.52% respectively in high and low traffic flow scenarios, while the optimization design reduced it by 42.71% and 65.60% respectively. The two-step street crossing caused a significant increase in left-turn non-motor vehicle delays, so it is not applicable when the flow of left-turn non-motor vehicles is high. The maximum motor vehicle traffic volume of conventional design was most affected by the flow of left-turn non-motor and straight-through motor vehicles. It indicates that avoiding the conflicts between left-turn non-motor vehicles and straight-through vehicles plays a significant role in improving the traffic capacity at intersections, which can be helpful for promoting the development of green travel.