American Society of Civil Engineers

Optimal Ramp-Metering Control for Freeway Corridors

by Yorgos J. Stephanedes, (Univ of Minnesota, Minneapolis, United States) and Kai-Kuo Chang, (Univ of Minnesota, Minneapolis, United States)

pp. 172-176

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Document type: Conference Proceeding Paper
Part of: Applications of Advanced Technologies in Transportation Engineering
Abstract: The paper discusses an optimal ramp-metering control model wherein a corridor is discretized into small road sections, with density as the state variable and ramp metering rates, the control variables. In each section the density dynamics are estimated by a continuum model developed with the conservation equation, and formulated as a state equation. The optimization process adjusts the metering rate of each ramp according to corridor traffic conditions such that the total corridor travel time during a certain period is minimum. The paper also presents a test of the optimal metering for a simple one-entrance-ramp segment of the freeway corridor. Fixed signal timing, upstream demands, diversion rates, turning percentages, and initial densities are known and the optimization period is three minutes.

ASCE Subject Headings:
Computer programming
Highway and road management
Traffic congestion
Traffic control devices
Traffic flow
Traffic management

Author Keywords:
Highway Traffic Control
Control Systems, Optimal - Transportation--Management
Continuum Models - Freeway Corridors - Open Loop Systems - Optimal Ramp Metering Control