Improving Intersection Safety and Operations Using Advance Warning of End of Green Systems (AWEGS)

Project Description

The Advance Warning of End of Green System (AWEGS) warns motorists on high-speed approaches to isolated traffic signals by flashing beacons on a "BE PREPARED TO STOP WHEN FLASHING" sign. The beacons are activated a few seconds before the onset of the yellow in the traffic signal to provide warning about the end of green. AWEGS was originally developed in an earlier project 0-4260. This project improved the AWEGS algorithm, deployed the improved algorithm at existing AWEGS deployments, and installed AWEGS at a new location. Researchers made the following improvements to AWEGS:

• Reduced false actuations
• Improved truck detection and treatment
• Designed and evaluated overhead sign configuration
• Developed failsafe operations due to detector failure
• Provided warning about the presence of queues
• Improved AWEGS interface

Researchers found that incorporating delay for detectors in the signal controller proves to be an easy technique to minimize false actuation. They found that an overhead sign combined with stutter flash significantly impacts approach speeds. The development of queue detection using stop bar detectors improves safety by continuing to flash the beacons at the beginning of green when a queue is present.

AWEGS improves safety on high-speed approaches to signalized intersections. For efficient and consistent operation, researchers recommend that AWEGS be deployed at locations having an average daily traffic of 15,000 or less. The system is now mature for implementation at applicable locations throughout Texas.

Project Publications

Enhancements to the Advance Warning of End of Green System (AWEGS) 0-5113-1

Improving Intersection Safety and Operations Using Advance Warning of End of Green System (AWEGS) 0-5113-S

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