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
To increase the safety and useful life of your steel bridges and steel traffic structures, consider going ultrasonic. Ultrasonic impact treatment (UIT) helps prevent fatigue cracking in welds and welded members of new bridges and structures by enhancing the geometry of the weld, introducing favorable compressive stresses, and relieving tensile stresses internal to the weld. Eliminating the fatigue cracking not only increases service life but reduces the overall lifetime cost of maintenance. UIT can also improve the performance of existing structures. Many in-service steel bridges and traffic structures were built before fatigue was understood and therefore have fatigue-prone details, such as cover plates and socket joints. Structure owners must continually monitor these details and often must retrofit them, which is costly and not always effective. Applying UIT minimizes the need for retrofits and extends the life of the structure.
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.
Reducing travel delays and disruptions caused by highway construction and increasing work zone safety are the twin goals behind the Accelerated Construction Technology Transfer (ACTT) initiative. Sponsored by the Federal Highway Administration (FHWA) and the American Association of State Highway and Transportation Officials' (AASHTO) Technology Implementation Group (TIG), ACTT promotes the use of innovative technologies and techniques to accelerate the construction of major highway projects. "A successful ACTT deployment is one that evaluates all possible options for acceleration of construction, including planning and design aspects of highway projects, for the benefit of the community and the traveling public," says Dan Sanayi of FHWA.
Highway construction projects are often delayed by problems with planning around and relocating utility lines. These delays are costly, time-consuming, and often unnecessary. A number of Federal Highway Administration (FHWA) resources provide guidance on reducing or avoiding these utility-related delays and the accompanying costs.