Flashing lights at intersections cause accidents, study says
Can a commonly used but dangerous roadway design cause more car accidents? A new study by University of Texas researchers claims the answer is yes.
Working with the knowledge that as many as 40 percent of all motor vehicle crashes occur at intersections, researchers studied the conditions under which car accidents took place. It found that three times the number of accidents happened at intersections with flashing lights compared to crossroads with stop signs. Numbers of accidents spiked significantly at flashing light intersections near highway entrance and exit ramps.
Study authors were not able to determine why more wrecks occurred at crossroads with flashing lights compared to other intersections. Speculation includes a theory that drivers are more confused about what traffic action to take when traffic lights flash. Researchers also wondered if there is a preference among traffic engineers to place flashing lights at certain intersections.
Some observers say drivers may misinterpret the meaning of flashing red or yellow lights. One driving school teacher thought that the lack of a solid pattern of color infused drivers with a "sense of urgency" and indecision.
Solid-colored traffic lights dictate one required action — stop, slow down or go. Traffic rules for flashing lights may include multiple actions, some based on a driver’s interpretation of the safe conditions to proceed through the intersection.
Of all the flashing light intersections studied by the Texas research team, the ones adjacent to highways appeared to be the most dangerous. The study noted that drivers exiting high-speed roadways had the greatest opportunity to crash, presumably because drivers did not slow down sufficiently to meet the off-highway traffic conditions.
The Texas University research is a preliminary study, which researchers say will be followed by another report expected to contain traffic design recommendations to help avoid motor vehicle accidents.
Source: NBC 5 Dallas-Fort Worth, "More Crashes at Intersections With Flashing Lights," Kevin Cokely, Dec. 20, 2011