为了给快速路网运行状况分析和控制策略评价提供高效辅助决策工具,提出快速路网宏观交通流仿真系统整体框架,分输入模块、仿真模块和输出模块三部分,并给出采用Microsoft Visual Basic面向对象语言开发的实现流程图和关键技术。仿真案例采用该系统对包含两个起点、两个终点的快速路网进行仿真,刻画交通拥挤的形成、传播和消散过程,并模拟ALINEA匝道控制策略情景下路网的运行状况。仿真案例表明,该系统能较好地描述网络交通流的时空动态演化,是测试、评价交通控制策略的有效工具。
In order to provide an effective method for traffic operation and evaluating different traffic control strategies for urban freeway network,this paper provides a macroscopic traffic flow simulation system for urban freeway.Whole framework of the system includes input module,simulation module and output module.Then it describes the program process and gives the main technical details via the object-oriented language Microsoft Visual Basic.Finally,taking the example of an urban freeway network with two origins and two destinations,this paper describes the process of generation,spreading and dissipation of the recurrent congestion.Besides,it simulates the effects of the ALINEA ramp metering strategy.Research results show that the system does not only do well in describing the evolution of the network traffic flow,but also testing and evaluating traffic control strategy effectively.