01333478

Component

https://doi.org/10.3141/2250-03

http://scholar.google.com...lett&publication_year=2011

Driver behavior within the dilemma zone can be a major safety concern at high-speed signalized intersections. The Nebraska Department of Roads (DOR) has developed and implemented an actuated advance warning dilemma zone protection system. This paper investigates the impact that system has had on safety at high-speed signalized intersections. The operating algorithm has been designed such that the system continually monitors an upstream detector, as well as traffic at the intersection, to predict the onset of the yellow signal indication. Flashing beacons are used to warn drivers of the impending end of the green indication. Although these systems have received positive reviews from the public—and commercial vehicle operators in particular—there has been no comprehensive analysis of their effect on safety. The focus of this research was to address this evaluative need and provide answers about the effectiveness of the Nebraska DOR system in improving safety. Crash records from before and after the implementation of the system at 26 intersections were compared. In addition, 29 control intersections were used to compare crash rates over time, and a fully Bayesian technique was employed to ensure that no exogenous variables affected the study. Results of the analysis were promising (an overall crash reduction rate of 8%) and suggested that the use of the system should be encouraged as an effective safety treatment for the dilemma zone problem at high-speed signalized intersections.

01360546

11-2561

English

pp 19-24

2011

Transportation Research Record: Journal of the Transportation Research Board

9780309167703

Print

Figures (1) ; References (28) ; Tables (3)

Advanced traffic management systems; Before and after studies; Crash rates; Dilemma zone; Signalized intersections; Traffic flow; Traffic safety; Warning systems; Yellow interval (Traffic signal cycle)

Bayesian approach; High speed intersections

Nebraska

Highways; Operations and Traffic Management; Safety and Human Factors; I73: Traffic Control; I83: Accidents and the Human Factor

TRIS, TRB, ATRI

Feb 17 2011 6:12PM

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