Portland State University

PSU Special Transportation Seminar:

An analytical derivation of the capacity at weaving sections consistent with empirical observations and micro-simulated results

Where: ITS Lab, Room 315, PSU Engineering Building

Summary: Weaving sections are discontinuities of the highway network formed when merge segments are closely followed by diverge segments. Because of their geometrical configuration, weaving areas generate numerous lane changes. Those lane changes lead to a reduction of the capacity and affect therefore the operation of weaving sections. 

This contribution aims at investigating empirically the lane changing behavior at a weaving section located in Grenoble (France). The data have been collected at a microscopic level, describing the position of every vehicle at every time step (trajectories of each individual vehicle). The data have been measured with a high-resolution camera mounted underneath a helicopter. 

From the empirical results, we develop an analytical formulation of the capacity of weaving sections. We consider a theoretical weaving section as the superposition of two merges and two diverges. We assume moreover that the accelerations and slowdowns of weaving vehicles create voids in the traffic stream that reduce the total capacity. The analytical estimation of the capacity is compared with field macroscopic data measured in Grenoble and micro-simulated results.

The specification of the needed data sample to...

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