Effectiveness of Blank-Out Overhead Dynamic Advance Warning Signals at High-Speed Signalized Intersections

Abstract

Advance warning signals are installed upstream of high-speed signalized intersections to warn motorists of impending signal changes. A new advance warning signal design was tested on an approach to a high-speed signalized intersection in Utah that utilized a dynamic blank-out sign with flashers mounted over the roadway. A state-of-the-art evaluation system was installed to collect continuous, nonintrusive data of vehicle speeds and red-light running events. Data were collected prior to and immediately after installation. Cumulative distributions of speed profile data showed statistically significant results after blank-out overhead dynamic advance warning signal (BODAWS) installation evidenced by an increase in mean speeds of 5–10 mph during the green interval, while the system was inactive, followed by a decrease in mean speeds of 5–10 mph after activation of the system. The system also reduced red-light running at the site during the time period immediately after BODAWS installation from five violations...