The North Carolina Department of Transportation reports that some relatively new traffic signals succeed in preventing accidents.
Since February 2005, 380 newly designed left-turn traffic signals have been installed at intersections across the sate. The first signal of its kind went up at the employee/visitor entrance to Wake Medical Center in Raleigh as part of a national study sponsored by the Federal Highway Administration.
The goal of these new signals is “to improve driver understanding of left-turn traffic signal displays and to reduce accidents at signalized intersections,” according to a press release from the NC DOT.
So far, so good. Of 39 sites studied, there has been a 37 percent decrease in accidents involving left turns at intersections with the new left turn signals.
These new signals include a flashing yellow arrow between the solid green and solid yellow arrows on what are commonly called “protected” left-turn signals. The flashing yellow arrow signals that left turns are permitted, but drivers must yield to oncoming traffic and—of course—pedestrians at the intersection.