47%

 for pedestrian crashes.4

98%

(varies by speed limit, number 

of lanes, crossing distance, 

and time of day).3

FHWA-SA-21-053

Rectangular Rapid 

Flashing Beacons (RRFB) 

A marked crosswalk or pedestrian warning sign can improve safety for 

pedestrians crossing the road, but at times may not be sufficient for drivers 

to visibly locate crossing locations and yield to pedestrians. To enhance 

pedestrian conspicuity and increase driver awareness at uncontrolled, 

marked crosswalks, transportation agencies can install a pedestrian 

actuated Rectangular Rapid Flashing Beacon (RRFB) to accompany a 

pedestrian warning sign. RRFBs consist of two, rectangular- shaped yellow 

indications, each with a light-emitting diode (LED)-array-based light source.1

RRFBs flash with an alternating high frequency when activated to enhance 

conspicuity of pedestrians at the crossing to drivers. 

Transportation agencies should refer to the Manual on Uniform Traffic Control 

Devices (MUTCD) for information on the application of RRFBs.1

 

1 Manual on Uniform Traffic Control Devices (MUTCD), Chapter 4L. FHWA, (2023).

2 “Rectangular Rapid Flash Beacon” in PEDSAFE: Pedestrian Safety Guide 

and Countermeasure Selection System. FHWA, (2013). 

3 Fitzpatrick et al. “Will You Stop for Me? Roadway Design and Traffic Control 

Device Influences on Drivers Yielding to Pedestrians in a Crosswalk with a 

Rectangular Rapid-Flashing Beacon.” Report No. TTI-CTS-0010. Texas A&M 

Transportation Institute, (2016).

4 (CMF ID: 9024) NCHRP Research Report 841 Development of Crash Modification 

Factors for Uncontrolled Pedestrian Crossing Treatments, (2017). 

Applications

The RRFB is applicable to many 

types of pedestrian crossings but is 

particularly effective at multilane 

crossings with speed limits less 

than 40 miles per hour.2

 Research 

suggests RRFBs can result in motorist 

yielding rates as high at 98 percent 

at marked crosswalks, but varies 

depending on the location, posted 

speed limit, pedestrian crossing 

distance, one- versus two-way road, 

and the number of travel lanes.3

RRFBs can also accompany school or 

trail crossing warning signs. 

RRFBs are placed on both sides of 

a crosswalk below the pedestrian 

crossing sign and above the 

diagonal downward arrow plaque 

pointing at the crossing.1

 The flashing 

pattern can be activated with 

pushbuttons or passive (e.g., video or 

infrared) pedestrian detection, and 

should be unlit when not activated.

Considerations

Agencies should:2

• Install RRFBs in the median rather

than the far-side of the roadway

if there is a pedestrian refuge or

other type of median.

• Use solar-power panels to eliminate

the need for a power source.

• Reserve the use of RRFBs for

locations with significant pedestrian

safety issues, as over-use of RRFB

treatments may diminish their

effectiveness.

Agencies shall not:2

• Use RRFBs without the presence of

a pedestrian, school or trail crossing

warning sign.

• Use RRFBs for crosswalks across

approaches controlled by YIELD

signs, STOP signs, traffic control

signals, or pedestrian hybrid

beacons, except for the approach

or egress from a roundabout.

RRFBs used at a trail crossing. 

Source: LJB

For more information on this 

and other FHWA Proven Safety 

Countermeasures, please visit 

https://highways.dot.gov/ 

safety/proven-safety-counter

measures and https://high 

ways.dot.gov/sites/fhwa.dot.

gov/files/2022-06/techSheet_

RRFB_2018.pdf. 

Safety Benefits:

RRFBs can reduce 

crashes up to:

RRFBs can increase motorist 

yielding rates up to:

OFFICE OF SAFETY

Proven Safety 

Countermeasures