Citation

Allen BL, Liew CJ. Transp. Res. Rec. 1975; 533: 88-96.

Copyright

(Copyright © 1975, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

This paper develops a simplified model for simulating freeway operations influenced by entrance-ramp metering or closure. The model's application to a real freeway corridor is demonstrated. The model is based on the assumption that that entire corridor can be adequately represented by only 2 routes interconnected by equally spaced entrance and exit ramps. Optimal control is achieved by minimizing total corridor travel time. The effectiveness of 3 control strategies (entrance-ramp metering, entrance-ramp closure, and total interchange closure) is investigated. Traffic flow on a real freeway corridor was simulated with this model. The model compared favorably with observed conditions. When the effects of the 3 control strategies were investigated, freeway flow rates resulting from optimal control conditions were found to be nearly identical for each strategy. Identifying the optimal flow rate permitted accurate calibration of the model and reliable results. The model can be useful for initial planning evaluations. Data requirements for the model are minimal, and its application is straightforward.