InTrans / Feb 14, 2017

Five Questions with Travis Hosteng concerning the National Center for Wood Transportation Structures

Travis Hosteng

Working primarily with the Bridge Engineering Center at Iowa State University’s Institute for Transportation, Travis Hosteng serves as the lead timber research engineer for bridges and structures, working with practitioners in the private and public sectors to address timber bridge and other structural engineering needs.

First off, how did you get involved with the NCWTS? What’s your role?
My current role is as the Center’s director, which entails managing and supervising timber research projects, maintaining a website with a mission of supporting all timber-related research and technology transfer, and fielding questions from university, industry, and private sectors related to timber bridge research and/or construction. My involvement in the Center truly began when I was in graduate school here at ISU, working on my research under the then-director Dr. Terry Wipf. That work, and the subsequent timber bridge research that followed, put me on this path to becoming the director nearly a decade later, a role I’ve served now for over two years.

Can you tell me a little about its’ history and purpose? How did the NCWTS become what it is today?
The history of the Center goes back to 1988 when Congress passed the Timber Bridge Initiative, establishing a national program to provide effective and efficient utilization of wood as a structural material for highway bridges with three primary designated program areas: demonstration bridges, technology transfer, and research. In 1992, the Federal Highway Administration (FHWA) became a partner in the program following the Intermodal Surface Transportation Efficiency Act (ISTEA) in 1991. In 2004, when funding ended for the program, the Forest Products Laboratory (FPL) moved to partner with ISU (together they had over 25 years of cooperative research in the area of timber bridges) and the National Parks Service (NPS) to fill the voids in research, education, and technical assistance to government agencies, industry, and research institutions.

Today, the Center directly conducts approximately $200,000 to $300,000 worth of research annually, often in cooperation with government agencies, universities, and private industry. This research is directed towards meeting the needs of an aging and deteriorating bridge inventory as well as developing ways to efficiently utilize a naturally sustainable forest resource.

Any particularly interesting research/projects currently being done?
One in particular comes to mind: This past summer, we finished a cooperative project involving ISU, NCWTS, FPL, FHWA, and Buchanan County, Iowa. This project involved the design, construction, and monitoring of a glulam girder bridge on geosynthetic reinforced soil (GRS) abutments. A live webcam view of the bridge can be found on the NCWTS website at The bridge is 52 ft long, 30 ft wide, and designed to HL93 standards. A large sensor array, somewhere around 80 to 100 sensors ranging from strain, tilt, moisture content, temperature, bearing load, etc., feeds continuous information related to the performance and condition of the bridge to a fully autonomous monitoring system that collects the data and sends it wirelessly to our office server where it is processed and analyzed and the results outputted 24/7/365.

How does work being done at the NCWTS impact local agencies in Iowa?
There are a few ways our work impacts local agencies, one of the more important currently is developing and distributing information related to cost-effective timber bridge alternatives to assist counties in meeting the demands of their aging infrastructure with limited budgets. In addition, I see a future for timber bridges in the realm of rapid, safe, high quality control (QC) bridge replacement or accelerated bridge construction (ABC). That means not just replacing obsolete bridges with timber bridges, but replacing them with engineered structures with construction being done in a controlled setting and a down time from road closure to road open of less than a week. This is already being done on larger high-profile state projects around the nation, and I think local agencies have much to gain by adapting this “technology” to their sector.

What are the biggest challenges you are seeing in the area of wood transportation structures?
Perception and lack of education. Number one, ask anyone about timber bridges and they’ll either describe the bridges of Madison County, Iowa, or a solid-sawn structure they once drove across. But ask a county engineer the same question, and deteriorating timber piles will likely be one of their biggest issues. These perceptions—that timber is outdated, rots over time, and is stick built—don’t accurately describe current timber products and timber bridges being built today in 2017. Demonstration projects, such as those completed by the NCWTS in recent years, have brought to light engineered glued-laminated timber bridge technologies; furthermore, other projects are supporting their use via inspections documenting their performance over time and speaking to their sustainability.