The National Cooperative Highway Research Program Project 3-54 orchestrated extensive efforts to identify the best traffic signal display for protected/permissive left-turn control. These research efforts arose from decades of practice, during which practitioners experimented with various displays and signal phasing schemes that either avoided, by design, normal safety problems or attempted to convey a clearer message to drivers on the correct right of way. Based on lab techniques and a real world implementation study of a flashing yellow arrow display in Montgomery County, Maryland, research findings are analyzed and discussed. Data from the Maryland study provided the research team with practical application information related to driver understanding, public response and acceptance, and political response and acceptance.
Abstract