Federal Highway Administration Grants TxDOT Approval to use RRFBs Statewide

The Federal Highway Administration (FHWA) granted the Texas Department of Transportation (TxDOT) interim approval for the use of Rectangular Rapid Flashing Beacons (RRFB) across the state of Texas as of Tuesday, Sept. 11.

RRFBs are user-activated amber LED signals that supplement warning signs at intersections or mid-block crosswalks. The signals are placed underneath pedestrian, school or trail crossing warning signs and can be activated by pedestrians manually by a push button or passively by a pedestrian detection system. RRFBs use an irregular flash pattern similar to emergency flashers on police vehicles and may be installed on either two-lane or multi-lane roadways.

The RRFBs were created as a way to draw more attention to pedestrian crossings and help curtail accidents. According to the National Highway Traffic Safety Administration, there were a total of 14,340 pedestrian fatalities and 193,000 pedestrian injuries resulting from pedestrian/vehicle crashes nationwide during the 2004-2006 period. RRFBs can enhance pedestrian safety by reducing crashes between vehicles and pedestrians by increasing drivers’ awareness of potential pedestrian conflicts on the road.

Although still a relatively new technology, the RRFBs have already proven to be successful. In a 2008 study, St. Petersburg, Florida, experimented with RRFBs at 18 pedestrian crosswalks. The city collected “before” and “after” data for one year at all 18 sites, and for two years at the first two implemented sites.

For the first two sites, the city collected data for overhead and ground-mounted pedestrian crossing signs supplemented with standard circular yellow flashing warning beacons, for comparison purposes, before the RRFBs were installed. The data showed more drivers yielded at crosswalks where the RRFBs had been installed in comparison to lower rates for standard warning signs. The higher yielding rates were sustained after two years of operation and no identifiable negative effects were found. The St. Petersburg data also showed that drivers yielded much farther in advance of crosswalks with RRFBs than with standard circular yellow flashing warning beacons.

In addition to the St. Petersburg locations, experimentation with RRFBs was also conducted at other uncontrolled marked crosswalks in Florida and other states. Those experiments showed similar results to those originally found in St. Petersburg.

There are also other benefits to using RRFBs, according to the FHWA. RRFBs are a lower cost alternative to traditional traffic and hybrid signals, and they increase drivers yielding at crosswalks significantly when supplementing standard pedestrian crossing warning signs and markings. In addition, the novelty and unique nature of the stutter flash may elicit a greater response from drivers than traditional methods.

The RRFBs may also increase the safety effectiveness of other treatments, such as the use of advance yield markings with YIELD (or STOP) HERE FOR PEDESTRIANS signs. These signs and markings are used to reduce the incidences of multiple-threat crashes at crosswalks on multi-lane roads (i.e., crashes where a vehicle in one lane stops to allow a pedestrian to cross the street while a vehicle in an adjacent lane, traveling in the same direction, strikes the pedestrian), but alone they only have a small effect on drivers yielding.

Although the RRFBs have been approved for use in Texas, currently there are no plans by either the FHWA or TxDOT to bring RRFBs to Irving. However, any jurisdiction wanting to install RRFBs can request permission from the Office of Transpiration Operations.

Written by Ariel Graham