Researchers at the Texas A&M Transportation Institute (TTI) are studying the effectiveness of rectangular rapid-flashing beacons (RRFB) in improving pedestrian crossing safety. Previous research has showed that the RRFBs increase the number of drivers yielding to crossing pedestrians, and the Federal Highway Administration (FHWA) has asked TTI to investigate modifications to the RRFB before adding the device to the Manual on Uniform Traffic Control Devices (MUTCD). Last year TTI examined flash patterns. Currently, they are investigating beacon placement.
“Several agencies are interested in having the RRFB added to the MUTCD,” said TTI Senior Research Engineer Kay Fitzpatrick. “Before it’s added to the MUTCD, FHWA was interested in learning if there were ways to improve the device.” As part of the current FHWA project, the research team conducted two studies—one on a closed course and another on an open road.
The closed-course study (at the Texas A&M University Riverside Campus) examined driver detection of a cutout pedestrian photograph in the presence of LEDs with various brightness levels, flash patterns, and locations within the sign assembly. One of the combinations tested was the pedestrian at the base of the sign near the beacon, which was flashing close to where the pedestrian was standing. This combination, rather than if the beacon was placed above the sign, requires more time for the driver to detect the pedestrian’s position. In other words, by having the flashing beacon above the sign, which is a greater distance away from a waiting pedestrian, the pedestrian would be more easily detected by drivers.
“We also wanted to investigate on the open road whether or not drivers would continue to yield in the same rates as they were yielding with the beacons below the sign,” said Fitzpatrick. “So we identified 13 test sites where the communities worked with us and move the beacons from below to above the sign. That way we had similar drivers and site characteristics when we collected data for both conditions – when the beacons were above the sign and when the beacons were below the sign. Therefore, the key variable that was changing in the study was the placement of the beacon.”
The open road study found that driver yielding was the same whether the beacons are above or below the sign, while the closed-course study revealed there are potential benefits to having it above the sign.
FHWA is planning to issue an official interpretation that will allow agencies to place the beacon above the sign before it is published in the MUTCD.
For more information about this project, please read the Techbrief: Comparison of Driver Yielding for Rectangular Rapid-Flashing Beacons Used Above and Below Pedestrian Crossing Signs.