Institute for Transportation

Approximately 41% of the 578,000 highway bridges in the United States are currently in need of repair or replacement (USDA 1995). Many of these bridges are short span crossings on rural roads and are ideally suited for wood construction. However, wood is seldom considered in the selection of a structural material for bridge construction because many engineers are unfamiliar or inexperienced with wood design.
For wood to be a viable material for highway structures,
engineers must have access to design tools that make timber design an easy and more familiar process. One such tool is standard plans that present a clear and concise design and are adaptable to a variety of parameters. This paper presents a summary of three sets of standard plans for timber highway structures developed through cooperative research at the
USDA Forest Service, Forest Products Laboratory: Standard Plans for Southern Pine Bridges, Standard Plans for Timber Bridge Superstructures, and Plans for Crash-Tested Bridge Railings for Longitudinal Wood Decks. Copies of these plans are available through the USDA Forest Service.