Abstract: Referring to the radiation ability of congestion center, the traffic congestion state was classified and the concept of degradation index of regional road network service was proposed. Based on the improved AHM model, five indexes, including saturation of road capacity, time-delay coefficient of traffic congestion, level of free flow, traffic volume and space occupancy, were selected to evaluate the regional road network service and build the degradation index model of regional road network service. Through different regional road network service degradation index, which was corresponding to different congestion degradation level, the proposed method was applied to Kunming trunk road network. The results verify that the quantitative results are consistent with the actual congestion situation, which proves the proposed method has good applicability. Through the research results, the proposed method is expected to provide a new method for evaluating the degree of urban road traffic congestion from the macro level, and to provide a certain reference value for improving the traffic environment and the level of traffic management.

Key words: traffic engineering, urban traffic, degradation index of regional road network service, AHM, traffic congestion, road network service level

摘要： 根据拥塞核的辐射力划分了交通拥塞的状态，提出了区域路网服务退化指数(SDI)的概念，基于改进的层次分析模型(AHM)，选取即时交通饱和度、拥堵延 时指数、自由度、交通量以及空间占用率等指标对区域路网服务水平进行评价，并构建区域路网服务退化指数模型。通过不同的区域路网服务退化指数，对应不 同的拥堵退化级别，并将此方法应用于昆明市主干路路网中进行验证，量化结果与实际的拥塞情况相符，证明此方法具有良好的适用性。通过研究成果，以期为 从宏观层面评价城市道路交通拥塞程度提供新的方法，以及为改善交通环境、提高交通管理水平提供一定的参考价值。

关键词: 交通工程, 城市交通, 区域路网服务退化指数, 层次分析模型, 交通拥塞, 路网服务水平