Evaluation of Lighted Pavement Marker Stop Bars at Intersections with Light Rail Lines

This paper presents an evaluation of the use of lighted pavement markers parallel to an intersection stop bar for three treatment intersections in Houston, Texas. The line of pavement markers was active, with a red light displayed from each marker during the red interval of the traffic signal. Each lighted pavement marker contained multiple LEDs, which operated such that each marker displayed an alternating wigwag pattern. The intended impact of the pavement markers was to reduce red light running violations and crashes on the intersection approach to an arterial that had an at-grade light rail line within its median. A before-and-after study was conducted to determine changes in crashes, red light running violations, and right turn on red violations at the study sites (right turns on red are prohibited at all the study sites). The analysis results showed that the lighted pavement markers reduced red light running violations at all three treatment sites, with two of the three reductions being statistically significant. Right turn on red violations were also reduced, and the reduction was statistically significant at all three treatment sites. A fourth site was chosen as a comparison (nontreatment) site, and the before-and-after study showed no notable change in the number of red light running violations or right turn on red violations at this site.