| The continuously worsened traffic congestion in metropolitan areas has seriously affected residents’work efficiency and the quality of life. Mitigating traffic congestions becomes a pressing task, and the management of key congestion roads is the key. Of the recurrent and non-recurrent traffic congestions, recurrent congestions are the most important issue in the congestion mitigation. Therefore, it is necessary to conduct the research on the identification of recurrent congestion segments and their spatial-temporal distribution characteristics in order to improve the effectiveness and pertinence of traffic congestion mitigation. In this context, by using Beijing as a case study city and based on its massive Floating Car Data (FCD), this thesis analyzed the characteristics of FCD, proposed identification and screen approaches for recurrent congestion segments based on three-level indices, and developed GIS application system for screening recurrent congestion segments. Further, this analyzed the characteristics of spatial-temporal distribution of the selected recurrent congestion segments in Beijing.First, based on a synthesis of existing studies on the spatial-temporal evaluation indices of traffic congestion characteristics and their corresponding analysis, the thesis analyzed the applicability of these indices for application to the identification and characterization of the recurrent congestion segments in Beijing. Then, it analyzed the characteristics of FCD in Beijing and determined that5minute was the appropriate time interval aggregation level of FCD for this research. Based on multiple days’ FCD data of the entire road network of Beijing, the study analyzed the characteristics of recurrent congestion segments, and developed three-level indices for identification and screening of recurrent congestion segments, including:(1) index of congestion intensity threshold,(2) index of congestion duration ratio, and (3) index of recurrent frequency. For the index of congestion intensity threshold, it established screening thresholds for the network level congestion index and segment level index for both peak and off-peak periods. For the index of congestion duration ratio, by using vehicle hour traveled (VHT) on different road classes as weights for calculation of the accumulated congested durations, it determined that the screening thresholds for peak and off-peak period are50%. For the index of recurrent frequency, by analyzing the ratios of accumulated mileage of multiple days’ congested segments, it determined the screening thresholds as80%.Second, in order to screen there current congested segments more efficiently and support researchers to analyze their spatial-temporal distributions, the thesis developed a GIS application system for screening the recurrent congestion segments based on VS2008and ArcGIS Engine. Further, it described the designs of system framework, system functional structure, and database. By combined use of the proposed three-level indices and two screening parameters, recurrent congested segments in Beijing city were selected.Finally, through an analysis of spatial-temporal characteristics of the selected recurrent congested segments, it is found that expressways and arterial roads comprise main road classes in recurrent congestion. The percentages of recurrent congested segment lengths for expressways and arterial roads are14.5%and8.6%for peak period, and8.9%and10%for off-peak period respectively. Further, there are apparent disparities and regularities in the distribution patterns of recurrent congestion in the morning and evening peak periods. The representative recurrent congested segments in the morning peak period include the western section of the Northern2nd Ring Road in both directions, the Eastern2ndRing Road in outer ring direction, the southern sections of the Eastern2nd,3rd, and4thRing Roads in inner ring direction, and the north section of the Badaling Freeway in the south bound direction. The representative recurrent congested segments in the evening peak period are mainly located in the north area of Beijing, including both directions of the north section of Eastern2nd Ring Road, Northern2nd Ring Road, and Western2nd Ring Road, and inner ring direction of the Northern2nd Ring Road and the Eastern3rd Ring Road. In the off-peak period, recurrent congestion segments are primarily located in the central area, with the inside area of the2nd Ring Road, the Eastern3rd Ring Road, and the Zhongguancun area being the representative. Further, the recurrent congestion segments gradually decreased from central to peripheral areas. |
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