Effectiveness of Rectangular Rapid Flashing Beacons for Pedestrian Safety: A Systematic Review

Abstract: Pedestrian-related traffic crashes constitute a substantial portion of total traffic crashes in urban areas that have become a critical public safety issue in the US. The number of pedestrian fatalities in the US has been on the rise over the past 15 years. In response, various countermeasures and safety treatments have been implemented at pedestrian crossings in order to reduce the risk of pedestrian-vehicle conflicts. These strategies range from pedestrian warning devices at mid-block crossings and the use of pedestrian signal heads at intersections and mid-block locations to the use of traffic calming measures like speed bumps, pedestrian islands, and curb extensions. Among these, mid-block crossing-locations where pedestrian crosses road outside of traditional intersections pose a unique challenge due to their unexpected nature for drivers and the higher speeds often associated with such areas. Ensuring pedestrian safety at these midblock locations, while also maintaining efficient traffic flow, is crucial for transportation agencies across urban, suburban, and rural town settings.
In this context, Rectangular Rapid Flashing Beacons (RRFBs) have emerged as a cost-effective and practical solution for improving pedestrian visibility and enhancing driver compliance at midblock pedestrian crossings. RRFBs are installed in a variety of contexts – urban, suburban, and rural town settings—where conventional traffic signals may not be warranted or deemed practical. Apart from the area context, it has been installed on lower-speed roadways such as near schools, hospitals, parks, as well as on minor collectors or on roadways through rural towns with relatively higher posted speed limits.
Numerous studies have been conducted to assess the impact of RRFBs on pedestrian safety in terms of crash reduction and/or drivers’ yielding behavior for pedestrian crossing at mid-block locations. However, despite the growing body of evidence supporting the effectiveness of RRFBs, questions remain about the optimal settings in which RRFBs should be deployed to maximize their benefits for both pedestrian safety and traffic operations. We conducted a systematic review of the literature to identify studies that evaluated effectiveness of RRFBs regarding pedestrian safety and traffic operations. This systematic review synthesizes existing research on RRFBs to evaluate their impact on pedestrian safety and traffic operations across diverse environments. By examining empirical studies, this review assesses the safety and operational benefits and limitations of RRFBs in terms of crash reduction, driver yielding behavior, and traffic operations. The review also aims to identify optimal conditions for RRFB deployment to maximize their effectiveness, particularly under varying speed limits and in different traffic contexts. In addition, the paper highlights gaps in the current literature and proposes directions for future research to refine RRFB implementation strategies and enhance pedestrian safety outcomes in diverse roadway settings.