Fuzzy Logics Based Traffic State Identification on Urban Expressway

The term "traffic state" has fuzzy features for its extension is ambiguous.Traffic flow characteristic itself and people's special knowledge are both indispensable.Thereby,based on the loop-detected-data on urban expressway,the paper introduces a knowledge-based fuzzy system to identify traffic conditions.By carefully analyzing various traffic phenomena,the principles and bases of traffic state classification,evaluation indexes,and fuzzy sets and fuzzy rules for state identification are presented.The method can dynamically demonstrate the area of congested traffic flow of the whole network,and will provide importance references for real-time traffic information promulgation and after identification and alleviation of traffic bottlenecks.