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Title: Recasting Dilemma Zone Design as a Marginal Cost-Benefit Problem
Accession Number: 01049656
Record Type: Component
Record URL: Availability: Transportation Research Board Business Office 500 Fifth Street, NW Find a library where document is available Abstract: One control objective at high-speed isolated intersections is to provide safe phase transition by minimizing the occurrence of high-speed vehicles in the dilemma zone before the phase is terminated. An upper limit for extending the green (maximum green time) is used to avoid an indefinite extension of the main-street green. Currently, the maximum green times are chosen by using engineering judgment. This approach does not explicitly consider the trade-offs between safety and delay and hence often results in both unsafe and inefficient performance at the intersection under medium to heavy traffic volumes. The dilemma problem is recast as one of minimizing the number of vehicles entering the upstream decision conflict zone (DCZ). An economic evaluation approach is proposed to maximize both safety and efficiency at the intersection by considering the problem in terms of marginal costs and benefits. Traffic conflicts are used to estimate potential safety benefits, and the induced delay cost is used to estimate the cost accrued on side-street traffic that is associated with extending a competing phase. This approach allows the implementation of logic that minimizes DCZ exposure instead of the current approach of absolute protection until the maximum green time is reached, at which time no consideration is given to dilemma zone exposure when the phase is terminated. This approach handles efficiently and safely the periods of moderate demand volumes when current dilemma zone protection frequently encounters maximum green time exposure.
Monograph Accession #: 01091263
Language: English
Authors: Sharma, AnujBullock, Darcy MPeeta, SrinivasPagination: pp 88-96
Publication Date: 2007
ISBN: 9780309104623
Media Type: Print
Features: Figures
(5)
; References
(35)
; Tables
(2)
TRT Terms: Uncontrolled Terms: Subject Areas: Highways; Operations and Traffic Management; I73: Traffic Control
Files: TRIS, TRB, ATRI
Created Date: Feb 8 2007 5:35PM
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