Red Turn Arrow: Safety Analysis

Although use of red turn arrows in traffic signals has been adopted by the Manual On Uniform Traffic Control Devices, a review of literature shows that there is great reluctance on the part of jurisdictions in using red turn arrow. This reluctance is rooted in the fear that the red arrow is an ambiguous and inherently unsafe traffic control device. Earlier studies of the red arrow did not present conclusive evidence of the parity or superiority of the red arrow in any traffic control setting. Based on observed violations of the red arrow and red ball at fifteen intersections of different types, located in different geographical areas, and more than 17,900 observed signal cycles, the study concludes that there is no evidence that the red arrow is less safe or more ambiguous than the red ball when used in equivalent traffic control settings. The study shows that the red arrow receives significantly less violations than the red ball, and appears to be more effective for exclusive turn control at T‐type intersections and at night time.