Characteristic analysis of traffic flow behaviors on beijing urban expressways

Key features of Beijing's urban expressways include a short distance between on-ramp and off-ramp, large traffic flow and high ratio of short-distance vehicles. An expressway control strategy should be based on these features. Accordingly, we selected three different sites on the Beijing Ring Road where the distance between on-ramp and off-ramp is about 300m. For each site we shot traffic videos on different dates and times including peak and non-peak hour sites. From the videos, we extracted traffic data, such as traffic flow, density and lane-changing behaviors. On the basis of these data, we analyzed the distribution characteristics of flow-density and lane-changing frequency. Finally, we compare the three sites and identify their common features. This will provide support for a future control strategy study on Beijing expressways. © 2012 American Society of Civil Engineering.