01506570

Component

https://doi.org/10.3141/2422-10

http://scholar.google.com...sson&publication_year=2014

Freeway congestion occurs mainly at discontinuities of the road network, such as merges, weaving sections, and diverges. Reliable tools are needed for estimating the operations at these discontinuities and evaluating their capacity. This paper proposes an analytical model that estimates the capacity at a diverging junction according to the kinematic wave theory of Lighthill, Whitham, and Richards. The model assumes that exiting vehicles drive temporarily at a speed that is lower than the free-flow speed. The slow vehicles are considered moving bottlenecks. In the methodology, the acceleration is assumed to be infinite in a first step. But, because it is a key factor in explaining the capacity drop, this assumption is relaxed in a second step through a constant acceleration rate used for all the vehicles. In this study, the moving bottleneck theory is used to compute the effective flow passing the diverging junction and the corresponding relative capacity drop. The analytical results are assessed with microsimulation results.

01541038

14-1625

English

pp 88–95

2014

Transportation Research Record: Journal of the Transportation Research Board

9780309295079

Print

Figures (6) ; References (25)

Bottlenecks; Diverging traffic; Freeways; Mathematical models; Off ramps; Traffic flow theory

Highways; Operations and Traffic Management; Planning and Forecasting; I71: Traffic Theory

TRIS, TRB, ATRI

Jan 27 2014 2:35PM

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