eNews • March 2014
Promoting a Cost-Effective, Reliable and Competitive Transportation System

STC’s Bridge Evaluation Project Presented to State Lawmakers

Iowa’s rural bridges need more than a visual assessment in order to properly determine structural safety and new technology developed at Iowa State University (ISU) could help the process. The message was shared by Mike Steenhoek, executive director of the Soy Transportation Coalition, and Brent Phares, director of ISU’s Bridge Engineering Center, with the Iowa House Transportation Committee.

Steenhoek told the committee that while safety is the ultimate consideration when evaluating bridges, there is more evidence suggesting that the current approach of visual inspection to evaluate bridges can be subjective and vary from one state to another. The new process of load testing a bridge takes the unknown out of the process, according to Steenhoek and Phares. The process includes installing sensors in strategic locations on the structures. A truck is driven across the bridge and the equipment records how the bridge responds under the load. Phares told the committee testing takes a day and it takes several weeks to analyze the data.

"I appreciate Chairman Josh Byrnes providing us the opportunity to present the results of our bridge evaluation project to the committee. One of the key messages of this project is that throwing more money at the problem is not always the answer,” Steenhoek said. Sometimes, simply practicing better stewardship of scarce taxpayer dollars will provide a solution. In this time of austere budgets, policymakers are becoming increasingly receptive to these kind of innovative approaches.”

Age is a big reason why more than 4,700 rural bridges are classified as structurally deficient by the National Bridge Inspection Standards. Officials says the structures aren’t unsafe, but have deteriorations, cracks or other flaws that reduce their load carrying capacity, which may cause weight restrictions.

“The availability of this technology sometimes falls through the cracks,” Phares said. “It wouldn’t be difficult to start at the top of the list and prioritize the bridges if we had the resources available.”

Phares said his staff currently has two complete testing systems, but they need more man power to conduct the tests. Currently, they can test about two bridges a week, but he said more staff would be needed to analyze the data and operate the systems that cost about $75,000 to $100,000 on a widespread basis.

“Liability exposure goes down as clarity goes up. Liability exposure goes down as subjectivity goes down. That’s what we’re driving at is removing that subjectivity from it so that there is a favorable consequence on liability,” Steenhoek told the committee.

Legislators asked multiple questions after the presentation ranging from the reliability of the new tests and how long it would take to test deficient bridges in the state.

“I have to say that this is the most intriguing presentation that I’ve sat through,” Rep. Joe Riding said.

Chairman Byrnes finished the committee meeting by thanking Steenhoek and Phares for the information.

“We have limited funding for infrastructure that we have in our state and we really have to pick and choose carefully where those limited dollars are going,” Byrnes said. “I think that sometimes we come under criticism for not being efficient enough with those dollars. Projects like this are truly being efficient and I think this is a good pathway to go. I also like the fact that there are a lot of partnerships here that will make this work and get more of this research done.”


The Soy Transportation Coalition is comprised of thirteen state soybean boards, the American Soybean Association, and the United Soybean Board. The National Grain and Feed Association and the National Oilseed Processors Association serve as ex-officio members of the organization.

Soy Transportation Coalition
1255 SW Prairie Trail Pkwy., Ankeny, Iowa 50023
Phone: (515) 727-0665 Fax (515) 251-8657
Email msteenhoek@soytransportation.org
Web www.soytransportation.org

Funded by the Soybean Checkoff