As mentioned in the updated June 2018 SAFE TRANSFORMATION FOR EVERY PEDESTRIAN countermeasure technical sheet from the US Department of Transportation (FHA), RRFBs can

REDUCE PEDESTRIAN CRASHES BY 47%.
It also says that multiple lanes create challenges for pedestrian crossing at unsignaled locations. RRFBs can make crosswalks and/or pedestrians more visible at a marked crosswalk.

• Discrete, Light and Thin Design
• Easy Installation on Standard Posts
• High-Intensity LEDS