01336945

Component

Yellow and all-red intervals are intended as a margin of safety. These are fixed intervals for signalized traffic approaches. However, some traffic patterns may not need the full designed intervals’ durations as a safety margin; while at other times, they are not sufficient due mainly to drivers trying to avoid to stop at the red light. The challenge for traffic engineers is to minimize the intersection delay and at the same time maximize intersection safety. A methodology for providing variable length yellow and all-red intervals, based on traffic responsive sensors and logical commands, is outlined. It is most suitable for intersections with high speed approaches. Basically, the yellow interval may be reduced but never terminated; however, the all-red interval may be terminated, reduced or extended based on safety requirements and delay considerations. The methodology stresses that safety is improved at some cases over the designed fixed yellow and all-red intervals, but never in any case safety is compromised lower than the default fixed yellow and all-red intervals. In addition, delay is reduced for various traffic patterns.

01329018

11-0511

English

13p

2011

Transportation Research Board 90th Annual Meeting

DVD

Figures (1) ; References (24) ; Tables (2)

Highway safety; Red interval (Traffic signal cycle); Sensors; Signalized intersections; Theory; Traffic delays; Traffic engineers; Traffic signal timing; Travel patterns; Yellow interval (Traffic signal cycle)

Highways; Operations and Traffic Management; I73: Traffic Control

Transportation Research Board Annual Meeting 2011 Paper #11-0511

TRIS, TRB

Feb 17 2011 5:28PM