中文摘要：

城市交通拥堵严重制约其网络总体效率。开展检测交通拥堵点可有效识别网络瓶颈，以整治交通拥堵现象。对此，本文提出一种新的城市交通时空拥堵点检测的方法：即采用实时路况数据，通过定义时空关联，检测时空意义上长期性、规律性交通拥堵点。本文基于DBSCAN（Density-Based Spatial Clustering of Applications with Noise）算法，以成都市为试验区，实现了这种拥堵点检测方法。试验表明，该方法可快速、有效、准确地检测出城市道路严重拥堵路段，并确定其拥堵时空范围，为交通管理、交通拥堵机理分析、交通拥堵预测等提供参考。

英文摘要：

Traffic congestion in urban road network heavily restricts transportation efficiency. Detecting traffic congestions in the spatio-temporal sense and identifying network bottlenecks become an important task in transportation management. Up to now, many traffic congestion detection methods have been pro-posed, which have focused on the detection of momentary local congestions. Larger-scale, longer-time and regular congestions can＇t be detected using these methods. That is because congestions have different tem-poro-spatial scales, and a characteristic is not considered in those methods. This paper proposes a new kind of urban traffic congestion detection method that deals with spatio-temporal extension of congestion. It is based on spatio temporal clustering analysis of real-time traffic data. By defining a proper spatio-tem poral correlation, the classic DBSCAN algorithm is adapted to tackle spatio-temporal clustering. With it we can detect longer time and regular traffic congestion in the spatio-temporal sense. Experiments have been conducted using real traffic condition data of Chengdu to validate the effectiveness of the method. The experiment shows that the proposed method can detect the congestion areas and identify the spatio-temporal extent of congestions accurately. The detected congestion areas were compared with congestion report from local traffic management authority and found to be consistent with the later.