01020664

Component

https://doi.org/10.3141/1959-02

http://scholar.google.com...witz&publication_year=2006

A novel switching traffic-responsive ramp-metering controller adapts to different traffic dynamics under different congestion conditions: free-flow or congested. The approach of multirate linear quadratic control with integral action is used to compensate for disturbances and to accommodate the difference between the model sampling time and the metering-rate update interval. In addition, a queue length regulator is designed to prevent the queue from exceeding the ramp storage capacity and yield improved performance over the current ad hoc queue override scheme. Subsequently, a queue length estimator is designed to provide feedback to the queue length regulator with the queue-detector speed data that are available in the field. A local ramp-metering control strategy is proposed to achieve the control goal of reducing the spatial and temporal span of the congestion, while satisfying the on-ramp storage capacity constraints, by using locally available information. Test results on a calibrated microscopic traffic simulator demonstrate the performance and effectiveness of the switching ramp-metering controller, the queue length estimator and regulator, and the overall control strategy. The total vehicle and passenger congestion delays are both reduced by 16%, and the total travel time is improved by 5.6%. As a comparison, simulation results of ALINEA are also presented.

01036675

English

pp 9-18

2006

Transportation Research Record: Journal of the Transportation Research Board

0309099684

Print

Figures (9) ; References (23) ; Tables (1)

Algorithms; Microscopic traffic flow; Microsimulation; Ramp metering; Traffic congestion; Traffic queuing; Traffic simulation; Travel time

ALINEA (Computer program)

Ramp storage capacity

Highways; Operations and Traffic Management; I73: Traffic Control

TRIS, TRB, ATRI

Mar 3 2006 10:55AM

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