The structural integrity of rural bridges is essential to farmer profitability. Unfortunately, an increasing number of rural bridges in the states are load limited, requiring vehicles transporting agricultural commodities to take a detour – often at significant distances. This inserts additional costs into the nation’s food delivery system and results in diminished profitability for farmers. While the need to maintain and upgrade rural bridges is increasing, the resources available to address this challenge remain insufficient.
In an effort to promote better evaluation and management of the rural bridges in Michigan, the Michigan Soybean Promotion Committee and the Soy Transportation Coalition have partnered with the Midland County Road Commission in central Michigan on an innovative project designed to demonstrate the effectiveness of load testing technology when assessing the condition of rural bridges.
“When managing and maintaining our county bridge inventory, motorist safety is the number-one priority,” said Terry Palmer, managing director of the Midland County Road Commission. “However, what we have learned is that the sole reliance on visual inspection of bridges can result in a percentage of bridges being unnecessarily load limited or identified for rehabilitation or replacement. This not only results in costly and unwarranted detours, but it prevents our local governments from most efficiently allocating scarce resources to those bridges in greatest need of replacement and repair.”
The partnership employs the use of load testing sensors attached to the underside of the bridge. After the sensors are installed, test loads are driven over the various segments of the bridge surface to determine a precise understanding of the capabilities of the bridge.
“The objective of load testing is to remove much of the subjectivity from the traditional visual inspection approach,” Palmer said. “In doing this project, it is our goal to highlight to Michigan counties and municipalities that this technology can be a cost-effective tool when managing and maintaining their bridge inventory.”
The jointly funded project began in the spring of 2017 and has so far resulted in the testing of three Midland County bridges. Each bridge originally had been load limited due to a perceived concern via the traditional visual inspection approach. However, after evaluating the bridges via load testing sensors, it was determined that each bridge did not require a load limit and could safely accommodate all legal loads for trucks operating in Michigan. Additional rural bridges will be evaluated in the upcoming months.
“Given that our children and grandchildren are using these rural bridges on a daily basis, safety is most important,” said Soy Transportation Coalition director Andy Welden, a soybean farmer from Jonesville, Mich. “Promoting this technology helps develop a better understanding of which bridges truly need repairs and which ones can safely handle the trucks that transport the soybeans and grain produced in the state. Michigan soybean farmers are pleased to help partner in this important project.”
Soy Transportation Coalition executive director Mike Steenhoek explained, “If we have a rural bridge problem in this country, which we do, and if resources to address this problem are scare, which they are, they we should do all we can to ensure we get the diagnosis correct. This project is designed to increase clarity of the condition of rural bridges and enhance stewardship of the bridges themselves and scarce taxpayer dollars. It is our hope that other states throughout the country will emulate this innovative approach.”
Steenhoek added that “public/private partnership” is a buzzword in transportation discussions. “While there are certainly examples of the success of public/private partnerships within transportation, they remain more of an ambition than an outcome,” Steenhoek said. “Our project is an example of a public entity – county government – and a private constituency – soybean farmers – partnering together by investing time, energy and resources to promote a solution.”
He said now that this project has produced compelling results, the coalition can proceed with seeing this innovative approach applied in other key areas where farmers are transporting soybeans to market.