Michael A. Knodler, Jr., Ph.D
University of Massachusetts - Amherst
Civil Engineering
Siby Samuel
University of Massachusetts - Amherst
Industrial Engineering
David A. Noyce, Ph.D., P.E.
University of Wisconsin - Madison
Civil Engineering




A Driving Simulator Evaluation of Red Arrows and Flashing Yellow Arrows in Right Turn Applications

Permissive left-turn and right-turn intervals have historically been communicated to drivers using nearly every traffic signal indication available, including the circular green (CG), flashing circular red (FCR), flashing red arrow (FRA), flashing circular yellow (FCY), and flashing yellow arrow (FYA) indications. The National Cooperative Highway Research Program (NCHRP) and other research demonstrated that, by most measures, the FYA indication is the most effective for communicating permissive left-turns. Therefore, the FYA indication was included in the 2009 edition of the Manual on Uniform Traffic Control Devices (MUTCD). More recently, agencies across the United States have increased the usage of FYA for use in right turns. While communicating the permissive nature of the right turn maneuver, the FYA has the added benefit of alerting drivers to the possible presence of conflicting pedestrians. The use of the MUTCD recommended display for this application is a four-section vertical with all arrow indications; however, this in turs results in a potentially confusing right turn on red condition for drivers facing a right red arrow. As the nationwide usage for FYA in right turn applications, there is specific need for research that addresses to critical elements: 1. What is driver comprehension of the FYA in right turn applications; and 2. What is driver comprehension of right turn on red requirements (RTOR) when facing a right red arrow.