The NCWTS is an information resource center at the Institute for Transportation, at Iowa State University.

Copyright © 2018, Iowa State University, all rights reserved.

About the National Center for Wood Transportation Structures (NCWTS)

In partnership with the USDA Forest Service, the Forest Products Laboratory, the Federal Highway Administration, and the National Park Service, the NCWTS integrates university and government research programs and supports a national demonstration and technology transfer program.

Beginnings of the timber bridge research program

In 1988, Congress passed the Timber Bridge Initiative (TBI), thus establishing a national program to provide effective and efficient utilization of wood as a structural material for highway bridges. Responsibility for the TBI was assigned to the USDA Forest Service, which designated 3 primary program areas:

  1. demonstration bridges,
  2. technology transfer, and
  3. research.

Demonstration bridges

The demonstration bridge program, administered by the National Wood in Transportation Information Center (NWITIC) in Morgantown, West Virginia, provided matching funds on a competitive basis to local governments to demonstrate timber bridge technology through the construction of demonstration bridges.

Technology transfer

The NWITIC also maintained a technology transfer program to provide assistance and state-of-the-art information related to timber bridges.


Responsibility for the research portion of TBI was assigned to the Forest Products Laboratory (FPL), the national wood utilization research laboratory of the US Forest Service. The primary focus of TBI research was the development of new and improved technology for timber bridge materials and systems. In 1992, the FPL research program was expanded to include wood transportation structures such as noise barriers, marine facilities, retaining walls, and sign supports.

Partnering with the Federal Highway Administration

Also in 1992, a substantial joint research program was initiated between the Federal Highway Administration's (FHWA) Turner-Fairbank Highway Research Center and FPL to implement the FHWA timber bridge research program mandated under the Intermodal Surface Transportation Efficiency Act (ISTEA) of 1991.

In subsequent years, the FHWA also initiated a substantial covered wood bridge rehabilitation and research program under the National Historic Covered Bridge Preservation Program mandated in 1999 by the Transportation Equity Act for the 21st Century (TEA21) and in 2004 by the Safe, Accountable, Flexible, and Efficient Transportation Act – A Legacy for Users (SAFETA-LU. To assist in implementing this program, the FHWA developed partnerships with FPL and the National Park Service.

New center formed

In fiscal year 2004, funding for the NWITIC ended, leaving significant voids in research capability, education, and technical assistance to governmental agencies, industry, and research institutions.

In response, FPL moved to establish the a research center centered around wood transportation structures at Iowa State University (ISU). FPL and ISU have more than 25 years of cooperative research in the area of wood bridges and extensive expertise in transportation structures. 

The new National Center for Wood Transportation Structures (NCWTS) was established and minimally funded in fiscal year 2007 as a university/government/industry partnership to provide greater program efficiency and leverage federal funding to maximize public benefit at minimal cost. Given the long standing cooperative relationship with FHWA, and the developing partnership with the NPS, both agencies were also included as partners in the new NCWTS at ISU. In addition, the FPL has been involved in wood transportation structures research for over 60 years.

How the NCWTS works

The NCWTS integrates university and government research programs and supports a national demonstration and technology transfer program. It also serves as an international center of excellence with an emphasis on the improved use, durability, and performance of wood transportation structures on primary and secondary roads and the rural transportation infrastructure.

Research may be accomplished entirely by the NCWTS partners but will more commonly be accomplished through cooperative efforts with universities, government agencies, and private industry.

Technology and information transfer is an important and integral part of the program and this internet site was established to provide readily accessible current information related to wood transportation structures research and demonstration including research needs, current projects, and publications.

Filling an important role

More than 25% of the United States' bridges are structurally deficient or functionally obsolete. The problem is especially critical on rural road systems where wood bridges offer many advantages due to their ease of construction.

The NCWTS can help agencies efficiently utilize naturally sustainable forest resources in appropriate transportation structures.

This joint national program and the creation of the NCWTS are particularly timely and valuable because wood bridges represent more than 27% of the Nation’s bridges and afford an opportunity to efficiently utilize naturally sustainable forest resources.