InTrans / Aug 14, 2018

Research on timber bridges and related topics: Research update

Timber bridges represent approximately 10% of the total bridges in the United States as stated in the 1994 National Bridge Inventory. In addition there area large number of bridges classified as steel, etc. that contain timber decks. For the most part these bridges are older structures that have lasted a number of years beyond the design life of the structure. States and local authorities continue to build bridges out of wood, as wood is considered a viable material for short span structures. Although wood has been used for a number of years, there are issues that need to be addressed through research as with any other material. The primary response to these issues has been the Timber Bridge Initiative passed by Congress in 1988. More recently, Section 1039 of the 1991 Intermodal Surface Transportation Efficiency Act (ISTEA) has included provisions for research and technology transfer into timber structures. The Timber Bridge Initiative has been charged to the USDA – Forest
Service; while the ISTEA program is the responsibility of the Federal Highway Administration (FHWA).