What the Heck is an RRFB?

By Debbie Bulger

Have you noticed the new flashing lights at the Rail Trail crossings?

The recently opened Westside Santa Cruz section of the Rail Trail has two RRFBs installed to increase safety for bicyclists and pedestrians crossing Fair Avenue and Swift Street. What’s an RRFB?

RRFB is traffic engineering talk for Rectangular Rapid Flashing Beacon. These flashing safety beacons consist of a diamond-shaped yellow sign with pedestrian and (in this case) bicycle icons, an LED array of high-frequency flashing lights, an arrow pointing downward to the crossing, and a push button to activate.


The push buttons are located on railings on both sides of the street intersection slightly before the trail crossings of Fair and Swift.

The push button on the railing as trail users approach the Swift Street intersection. Beacon lights start flashing immediately after the button is pushed.

RRFBs are often powered by a solar panel eliminating the need for expensive wiring. Unlike some flashing lights which do not come on right away, the RRFB is activated immediately after the button is pushed.

The strobe-like flashing lights alert drivers that pedestrians and bicyclists are crossing the street. Research has shown that the use of an RRFB increases driver yield rates up to 96% and can reduce crashes by 47%.

Do Drivers Always Stop?

The presence of these beacons does not mean that the bicyclist or pedestrian can cross the street without looking. Drivers are supposed to yield to pedestrians and bicyclists in the crosswalk. Sometimes they do not. When I checked out the crossings recently, several drivers raced through the intersection in front of me. Vehicle traffic on Swift Street appeared to be faster than vehicle traffic on Fair Avenue.

Most bicyclists and pedestrians crossing on the Rail Trail have not been pushing the activation button but instead look for a gap between vehicles to begin crossing the street. It is a good idea to push the button, however, to get drivers used to trail users crossing at these intersections.

Many drivers think of intersections as only occurring where two streets cross and are less aware that the crossing of a multipurpose trail and a street is also an intersection. The RRFB alerts drivers that there is bike and pedestrian traffic in the crossing and that drivers must yield according to the law.

The City of Santa Cruz has installed these flashing beacons at many other crossings including on Delaware Avenue, East Cliff Drive/San Lorenzo Riverwalk, and Soquel Avenue/Cayuga Street.


Debbie Bulger is the author of “Secret Walks & Staircases in Santa Cruz and the coordinator for Mission: Pedestrian, a Santa Cruz pedestrian advocacy group.

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