AZ Interstate Median Safety and Crossover Crash Analysis Study

Although the Manual on Uniform Traffic Control Devices (MUTCD) does not require the use of warning lights on channelization devices, the Arizona Department of Transportation (ADOT) has historically required their use on all traffic control devices used at nighttime construction zones. This report documents research done for ADOT on the use of steady-burn warning lights on vertical panels in roadway construction zones. Specific tasks included a review of the requirements and policies of the departments of transportation of other states regarding the use of flashing warning lights on traffic control devices, a review of ADOT’s construction zone requirements, a search for relevant research, reviews of construction zone accident reports and incident logs, and interviews with ADOT field construction staff regarding the past performance of the Ultra Panels (Type III sheeting) with and without steady-burn warning lights.