Project Title: Advance Warning for End-of Green Phase for High Speed Traffic Signals

Sponsor: Texas Department of Transportation

Principle Investigator: Carroll Messer

Research Staff:

TTI Project Number: 442602

Start Date: 9/1/01

End Date: 8/31/02

Abstract: Texas has become the second most populous state in America and population growth continues at a rapid pace. Consequently, traffic signals are being installed more frequently at high-speed and high-growth rural intersections because of higher traffic volumes due to the urban-rural migration. Most of these intersections have posted speed limits above 50 mph and in some instances 70 mph. One of the major difficulties with traffic signal operation on high-speed approaches is the dilemma an approaching motorist faces when the signal turns yellow. Should the motorist stop or proceed through the intersection? Crashes that occur at these intersections result in high property damage and personal injury due to the high speeds involved. This project will research the use of advance flashing beacons and/or other methods to provide advance warning to motorists of the end of the green signal phase. Both state-of-the-art and advanced technology system designs will be developed and tested from which the most efficient system designs can be recommended for statewide application. Six field tests of various design features (including warning devices, system communication methods, vehicle detection devices, and signal controllers) are proposed over the two-year study period. Practical application criteria, design guidelines, and signal deployment methods will be delivered in a series of manuals at the conclusion of the project together with traditional research reports that fully document the work conducted and findings obtained.