Study On Traffic Flow Characteristics And Capacity In A-weaving Area Of Urban Expressway

Weaving area is one of the important components of urban expressway system. Thetraffic flow characteristics and capacity of weaving area is an important prerequisite forfacility planning, design, traffic organization and administration. It is the bottleneck of roadsystem because of the disturbing operation in it and issues about it are difficult to solveresulting from its complexity. So the thorough and systematic research on it is reallynecessary.In this dissertation, traffic flow characteristics and capacity of A-weaving area in urbanexpressway have been focused on and researched.According to previous research on weaving areas all over the world, many analysismethods are brought forward and summarized. Field data of weaving operation are collectedand weaving areas traffic flow characteristics are analyzed from these field data, such astraffic flow, speed, vehicle following characteristics, changing lanes characteristics, therelationship between the basic parameters of the traffic flow etc. As a result, the weavingoperation process and its influencing factors are got from the above analysis.Subsequently, the paper has designed the experiment about three parameters (weavingarea length, weaving flow ratio and the proportion of large vehicles) which mostly influencethe capacity of weaving areas, and has used the traffic flow characteristics analysis as thebasic data and the VISSIM simulation software as the experiment platform. Through theoperation of the experiment, this paper discussed the relationship between the threeparameters and the capacity of the weaving areas, and then calculated the capacity formula inconformity with driving characteristics of A-weaving areas of three-lane urban expressway inXi’an.Finally, the paper analyzed the level of service of weaving areas, and then summarizedthe LOS classification standard and the analysis methods of A-weaving areas of urbanexpressway.