There is a body of research that suggests the flashing yellow arrow displays, also known as the four-section signal heads, are more easily understood by drivers. As a result, there is a trend statewide toward using the four-section signal heads in place of the five-section head, which has a solid red, yellow and green light as well as a yellow and green left-turn arrow, said Buddy Murr, state signals engineer for the N.C. Department of Transportation.
Data compiled by the N.C. DOT in 2009 and 2010 showed a 37 percent drop in left-turn related crashes at intersections where the five-section head was replaced by the four-section head. Murr said traffic officials believe that when drivers see the flashing yellow arrow of the four-section head they are more apt to slow down and cautiously negotiate the intersection than when they see the solid green light on the five-section head (also known as the doghouse head). One of the problems with the five-section head, Murr said, is that some drivers mistakenly think the solid green light gives them the right-of-way to turn left.
National studies have shown similar findings, prompting the National Highway Traffic Safety Administration to recommend the four-section head in place of the five-section one.
In Wilmington, there are 22 intersections with a flashing yellow arrow display:
Of those intersections, a little less than half made the Wilmington Police Department’s Top 100 intersections with the most traffic accidents from Jan. 1, 2006, to Aug. 31, 2011.
Date posted: September 7, 2011
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