Citation

Tydlacka J. IMSA J. 2011; 49(3).

Copyright

(Copyright © 2011, International Municipal Signal Association)

DOI

unavailable

PMID

unavailable

Abstract

This article presents an evaluation of 2 supplemental traffic control devices, a Lighted Stop Bar System (LSBS) and light emitting diode (LED) outlined traffic signal backplates. The LSBS consists of lighted pavement markers placed in the pavement parallel to the painted intersection stop line. The pavement markers contain LEDs which emit a red light during the red signal indication of the traffic signal. The LED outlined backplate emits a red light around the perimeter of the traffic signal backplate when the traffic signal indication is red. The intended impact of the devices was to reduce red light running (RLR) violations and crashes on intersection approaches to an arterial with an at-grade light rail line within the median of the street. These 2 types of devices were installed separately at different intersections, and before and after studies were conducted to determine changes in crashes, RLR violations, and right turn on red (RTOR) movements, which are prohibited at the study sites. From analysis results, it was determined that the intersection with the LED outlined backplates exhibited significant reductions in RLR violations, and minor reductions in RTOR violations. Multiple sites with the LSBS were evaluated, and significant reductions were noted for both RLR and RTOR violations after the LSBSs were installed.