关于城市快速路控制与管理的若干讨论

Discussions of the Management and Control of Urban Freeway/Expressway

利用理论推导和系统仿真等方法分析了有关城市快速路交通控制的一些基本问题,包括入口匝道车流控制,出口匝道排队控制,快速路交通优先等.分析结果表明:(i)入口匝道控制虽然增加了入口排队延误,但是对整个快速路系统来说,可以提高系统的效率.(ii)入口匝道控制对普通道路既有正面影响,也有负面影响,合适的入口匝道控制策略甚至能同时对快速路和普通道路系统有益.(iii)在出口匝道相连的信号交叉口采用考虑出口排队的感应控制算法,可有效避免出口匝道排队阻塞快速路的现象,虽可能对普通道路有些负面影响,但是对整个交通网络有益.

The paper discussed some basic problems in urban expressway/freeway traffic management and control by theoretical and simulation approaches. Discussions cover the topic of on-ramp traffic control, off-ramp queue length control and expressway traffic priority, etc. Results of analysis show that: (i) although ramp-metering control can increase the delay on ramp, it can also increase the efficiency of the whole traffic system including urban freeway and ramp; (ii) ramp-metering control has positive and negative effects to the network traffic, and optimized ramp-metering algorithm can bring forth the positive effect on both urban freeway and network traffics; (iii) off-ramp queue may effectively be controlled by using queue length controlled signal controllers. This will avoid the excess off-ramp queue effectively and increase the operational efficiency of urban freeway and the whole traffic network.