The NCWTS is a center at the Institute for Transportation, at Iowa State University.

Copyright © 2015, Iowa State University, all rights reserved.

ASCE's National Timber Bridge Survey


ASCE National Timber Bridge Survey map

ASCE's National Timber Bridge Survey
State color by percentage of total timber bridges in USA


The National Bridge Inventory provides limited information related to timber bridges in the United States—they represent about 5% of total bridges and exist in all 50 states. ASCE's Timber Bridge Committee has undertaken a nationwide survey seeking information about timber bridge use along with owner's perceptions about advantages/disadvantages of timber bridges. The survey will determine the extent of the use of wood for vehicular bridges and assess concern that bridge owners might be experiencing. Information related to span length, type/configuration, design methodology, preservative treatment, railing treatment, wearing surface, and recent construction practice is included. Results will be provided to the American Association of State Highway and Transportation Officials and may lead to potential further investigation and/or research.