Drivers are allowed to turn right during red lights 24 hours a day at most urban intersections with traffic signals in the United States. The practice, intended to reduce delays and fuel consumption, also increases the risk of crashes and injuries, especially to pedestrians.
Strategies to reduce the risk of pedestrian crashes start with banning the whole practice of turning right on red. Other possibilities include prohibiting the practice during certain hours or prohibiting it when pedestrians are present. Institute researchers evaluated these options, finding that time of day restrictions have the potential to reduce crashes. Signs giving drivers discretion aren't as effective.
For the study, 15 intersections in Arlington, Virginia, were randomly assigned to three groups — one where right turn on red was prohibited during specified hours, one where the turns weren't permitted when pedestrians were present, and a control group of intersections where right turn on red continued to be allowed as before. To judge effectiveness, the researchers considered the number of drivers who failed to stop before turning and the number who stopped at designated stop lines. The number of pedestrians yielding to turning vehicles also was considered, because yielding increases the risk that a pedestrian still will be in the crosswalk at the end of the allotted crossing time. This increases the risk for elderly people who walk slower.
Signs prohibiting right turns on red from 7 a.m. to 7 p.m. increased the percentage of drivers who stopped at stop lines from 21 to 40 percent and reduced the number of drivers who turned right on red without stopping (32 to 13 percent). The number of pedestrians who yielded to turning vehicles decreased from 17 to 7 percent. At sites posted with signs prohibiting right on red when pedestrians were present, there was little change overall.