基于元胞自动机模型的高速公路可变速度限制交通流特性分析

摘要

Based on symmetric two-lane Nagel-Schreckenberg (STNS) model, a cellular automaton model of variable speed limit section in freeway is established with access to real-time traffic information of intelligent transportation system (ITS). The effects are discussed about how the different speed limit values, the lengths of speed limit section, and the different traffic states affect the traffic flow and the traffic volume via the simulation experiment of dynamic speed control. The effectual condition of speed limit is analyzed. The results of the examples show that speed limit can be used solely under some traffic states as an assistant traffic management strategy. The traffic jam phenomena can be suppressed and the goal of achieving a largest traffic flow and reducing the passing time of vehicles can be realized by using the dynamic speed control method with the different speed limit values and lengths under some traffic states.%在STNS模型的基础上，建立了可利用智能交通系统实时信息的高速公路可变速度限制区段元胞自动机模型，对动态速度控制区段的交通流特性进行模拟，分析了不同有效限速值、区段长度与交通状况下的限速对交通流和道路通行能力的影响，以及限速有效性条件．模拟结果表明可变速度限制作为交通管理控制的辅助手段，具有一定的使用条件，针对不同交通状况采用不同的最优限速值和区段长度的动态速度控制方法，可在保证交通安全的前提下达到抑制交通拥堵、减少车辆总通行时间从而提高道路实际通行能力的目的．