U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
|Accelerating Infrastructure Innovations|
Publication Number: FHWA-RD-03-019
Date: July 2003
The Technology Implementation Group (TIG), which was started in 2001 to champion the implementation of ready-to-use technologies, products, or processes resulting in economic or qualitative benefits, has chosen three new technologies for accelerated deployment in 2003. The 2003 selections are the Thermal Imaging Safety Screening System (TISSS) for Commercial Vehicle Brakes, the Low Cost Highway Rail Warning System, and Fiber Reinforced Polymer (FRP) Repair of Overhead Sign Structure (OSS) Trusses.
The TIG is sponsored by the American Association of State Highway and Transportation Officials (AASHTO). Over the next several months, TIG members will be developing plans to promote the new focus technologies among State highway agencies, local agencies, and industry partners. As these plans are further developed, Focus will provide updates.
The TISSS was designed, constructed, and tested for use in the selection of commercial vehicles for safety inspections at Georgia weigh stations. The system allows an operator at a weigh station to view the relative temperatures of brake drums, as seen through the wheel rims of commercial vehicles. If a brake system is operating correctly, an infrared vision will show all the brake drums to be hot and at approximately the same temperature when the vehicle is braking. If a brake is defective, the brake drum will appear to be the same temperature as the wheel rim and darker than a properly operating brake. The TISSS was tested on I-20 near Atlanta at the Douglas County weigh station for a 1-month period in April 2002. The system was deployed in three configurations: 1) adjacent to the weigh station entrance ramp; (2) adjacent to the ramp leading to the static scales at the rear of the weigh station; and (3) adjacent to the static scales. The prototype system proved to be effective in detecting brake problems, with the third configuration deemed the best. In this configuration, the system was used to screen only those vehicles being weighed and was operated by a weigh station employee concurrent with weighing operations. Only minimal operator training was required. A computerized video capture system allowed for viewing, storage, and printing of selected images.
The Low Cost Highway Rail Warning System was developed to replace passive crossing warning signs at low volume highway and railroad at-grade intersections with an active wireless warning system. The system consists of hardware installed in the locomotive that communicates with individual devices mounted on standard crossing poles to activate the signal and provide data on the crossing. The crossing pole devices are solar and battery powered and can be installed for only about 10 percent of the cost of a traditional warning system. The system is currently being tested in Minnesota at 11 intersections. Test results to date have indicated that no trains have passed without successful activation of the system within the required parameters for advanced warning.
FRP repair of OSS trusses has been studied by the New York State Department of Transportation (NYSDOT) and the Utah Department of Transportation. OSS's provide valuable information to drivers, but can become a serious hazard if they are not properly maintained. The NYSDOT organized its first sign inspection program in 2000 and found that 10 percent of all sign structures had some form of structural damage. The most prevalent damage found was cracking of the joint between the internal trussing and the main chords, with some joints totally severed. After an FRP manufacturer proposed using FRPs to repair the cracked truss joints, New York and Utah joined forces to form a Pooled Fund Research Program to study the feasibility of using FRP. Test samples of cracked joints were removed from existing OSS's that had been taken out of service. These samples were then wrapped with FRP and sent to the University of Utah for tensile testing. The repairs proved to be as strong as if the joints had been fully welded. A second round of testing is now being done to determine the resistance of the FRP repair to cyclical loadings.
For more information on TIG, visit the TIG Web site at www.aashtotig.org.
TIG Focus Technologies Contacts
Gary Hoffman, Pennsylvania Department of Transportation
Highway Rail Warning System
David L. Huft, South Dakota Department of Transportation
Paul Wells, New York State Department of Transportation
TIG Focus Technologies Previously Selected
Accelerated Construction ITS Technologies in Work Zones Prefabricated Bridge Elements and Systems
Air Void Analyzer Ground Penetrating Radar Global Positioning System