American Society of Civil Engineers

Algorithm and Application of Traffic Flow Characteristics Coordinated Analysis for On-Ramp and Adjacent Intersections

by Li-xia Bao, (ITS Research and Development Center, Shang hai Urban Construction Design and Research Institute. E-mail:, Xiang Gao, (ITS Research and Development Center, Shang hai Urban Construction Design and Research Institute. E-mail:, and Xiao-xiao Xu, (College of Transportation Engineering, Southwest Jiaotong University. E-mail:
Section: Traffic Flow and Transportation Network Theory, pp. 1889-1897, (doi:

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Document type: Conference Proceeding Paper
Part of: ICCTP 2010: Integrated Transportation Systems: Green, Intelligent, Reliable
Abstract: Traffic flow models and algorithms for ramp access areas are an indispensable theory of signal metering control, which is an efficient method to control merging traffic flow for busy expressways. In this paper, a traffic flow characteristics analysis of an urban expressway on-ramp and adjacent intersections is studied. Most studies are concerned with uninterrupted traffic flow, primarily on freeways or expressways. Traffic flow for on-ramps and intersections is interrupted, especially when congested. To solve the collaborative difficulties and limitations of a traditional uninterrupted and interrupted traffic flow model, an innovative area traffic flow model is presented, in which the interactions among vehicles, drivers, and the infrastructure are described in a precise mathematical way. The on-ramp traffic state is computed with occupancy and congestion rates, and access traffic flow with intersection lane flow is strong associated with traffic parameters, including volume, capacity, cycle, green split, etc., so as to realize the coordination of ramp metering and intersection signal control. The model is applied to the case of the South Wanping Road on-ramp and the South Wanping Road-South Zhongshan Road intersection. Actual traffic data were collected, and the on-ramp traffic state and the associated characteristics were analyzed. Simulation results show that the method is sufficient in providing an accurate traffic flow analysis. With the optimized ramp metering and intersection control strategy, the test traffic corridor’s capacity is improved by 15 percent, and the vehicle delay is decreased by 17 percent.

ASCE Subject Headings:
Traffic flow
Traffic models