In Sullivan City, Texas, a signal control system that gives priority to trucks has reduced truck stops by 100 for a weekly volume of 2,500 trucks and has reduced truck delay.
Made Public Date
06/11/2001

459

Sullivan City
Texas
United States
Identifier
2007-00383
TwitterLinkedInFacebook

Reducing Truck Stops at High-Speed Isolated Traffic Signals

Summary Information

This study examined the implementation of a traffic signal preemption system used to give trucks priority at a high-speed intersection (US-83 and FM-886) in Sullivan City, Texas. The Texas Department of Transportation installed a pair of magnetic loop detectors under the pavement 550 feet upstream from the intersection in order to identify trucks and determine their individual speeds. The loop detectors were connected to a Traffic Counter/Classifier (TCC) and a personal computer capable of communicating with and activating intersection signal control devices. Based on the signal phasing plan and truck speed data input, the computer placed holds on signal timing as necessary to extend green time for approaching trucks. The duration of each hold was based on truck speed. If a truck was identified during a red light, no hold call was placed. A timer relay was also used to limit hold times to 2 minutes in order to reduce the excessive wait times resulting from consecutive truck actuations.

The data was collected and analyzed to evaluate the impact of using the preemptive signal control system to minimize truck stops. The research team collected data three weeks before implementation, and then three weeks after. The "before" and "after" data were collected during typical traffic volume conditions.

FINDINGS

The signal control system benefited about four percent of the trucks on the roadway since holds were placed only when trucks needed extended green time. For a weekly volume of 2500 trucks, 100 less stops were made.

Reducing Truck Stops at High-Speed Isolated Traffic Signals

Reducing Truck Stops at High-Speed Isolated Traffic Signals
Publication Sort Date
09/01/2000
Author
Sunkari, Srinivasa R., et al.
Publisher
Texas DOT

(Our website has many links to other organizations. While we offer these electronic linkages for your convenience in accessing transportation-related information, please be aware that when you exit our website, the privacy and accessibility policies stated on our website may not be the same as that on other websites.)

Application Taxonomy

Goal Areas
Deployment Locations