Publication Detail

Safety Effects of the Yellow Light Border (YPB) Pedestrian Signal: An Evaluation Study

UCD-ITS-RR-19-63

Research Report

Suggested Citation:
Musabbir, Sarder Rafee, Shenyang Chen, Michael Zhang (2019) Safety Effects of the Yellow Light Border (YPB) Pedestrian Signal: An Evaluation Study. California Department of Transportation

The conflict between pedestrians using crosswalk and turning traffic at intersections poses a safety risk to pedestrians. To mitigate the risk, Caltrans engineers conceived a new safety feature for pedestrian signal – Yellow Pedestrian Border (YPB). YPB is a new feature that a yellow LED light border is added around the pedestrian signal (See Picture 1). YPB is a supplement to the existing standard pedestrian signal display, which provides a direct feedback to pedestrians who push the crosswalk button. Furthermore, YPB also makes the pedestrian signal more visible, which alerts drivers that the pedestrian signal is about to serve a crosswalk. A preliminary study conducted in Redding, CA, demonstrated the benefits of YPB and its impact on pedestrian safety. This research is an extension to the preliminary study, which aims at testing and assessing the YPB safety benefits at different locations and traffic conditions.
This study was carried out following a previous study by in Redding, California, with a goal to evaluate the anticipated benefit of the yellow pedestrian border signal in a more diverse setting with five different locations around California. The study aims to determine whether the additional feature to the traditional pedestrian signal provides an overall benefit to both vehicular traffic and pedestrians, resulting in improved interactions between vehicles and pedestrians at intersection. The improvement is measured and evaluated by comparing different type of conflicts, violations, and extra-push events for before and after YPB installations.

Key words: pedestrian signal, yellow LED, yellow pedestrian border