Abstract: The current evaluation methodology of Level of Service(IDS)is respectively carried on the segments，intemections and weave sections． For highway network，there is not a unform criteria and a practical methodology to evaluate LOS．This paper presents a new methodology to evaluate LOS of highway network by traffic simulation technica1．Two index parameters are used in the proposed method：the average speed and the degree of saturation(v／e)．The method is applied to the evaluation of a highway network with the aid of traffic simulation software TSIS．From the example，it can be concluded that it's practicable to evaluate the network LOS with uniform method．The method is simple in principle and practical for application．

Key words: highway, traffic simulation, highway network, LOS

摘要： 现行的公路服务水平评价，分别针对基本路段、交叉口、交织段进行评价，而路网的服务水平评价缺乏一致的 标准和实用的方法．本文着眼于系统，对组成路网的各要素(基本路段、交叉口、交织段、匝道等)均采用速度和饱和 度(v／c)作为评价指标，基于交通仿真提出了公路路网服务水平评价的方法，并结合交通仿真软件'ISIS给出了服务 水平评价的实例，算例显示采用统一的评价方法对路网服务水平进行定量评价是可行的，该方法原理简单，实用性 强．

关键词: 公路, 交通仿真, 路网, 服务水平