ANKENY, Iowa – Almost a quarter of Iowa?s rural bridges are structurally deficient, according to a recent study from Washington D.C.-based non-profit TRIP.
Across the United States, eleven percent of rural bridges are structurally deficient, meaning they exhibit significant deterioration on the bridge deck itself. Additionally, ten percent of U.S. bridges are functionally obsolete and no longer meet current highway design standards.
There are a few reasons that 22 percent of Iowa?s bridges have deteriorated; for one, there?s a lot of them. The Iowa DOT estimates more than 24,000 across the state. Additionally, throughout the 20th century rural residents moved into urban areas, leaving fewer taxpayers in remote areas to fund bridge repairs and maintenance. Short of the recent ten-cent fuel tax increase, funding on the state level has been elusive.
Soy Transportation Coalition Executive Director Mike Steenhoek says all of that adds up to a crumbling infrastructure that leaves agriculture in the 21st century dependent on 20th century infrastructure.
?We?ve had this amazing progression and evolution within the agricultural industry, from the
seeds that are used, to the equipment that?s used to plant and harvest, to how those agricultural products are marketed,? Steenhoek notes. ?But when you juxtapose that progression within the industry to the rural roads and bridges that farmers depend upon, there?s a pretty significant chasm between the two, and our rural roads and bridges are very reminiscent of what people would?ve experienced in the 1940s and 1950s.?
To solve the problem, Steenhoek says the Iowa Soybean Association is chasing $250,000 in state funding, in addition to its own $50,000 commitment, to use Iowa State University technology to asses bridge structures using electronic sensors and trucks hauling loads of certain weights.
The new project is a successor to efforts in 2013 between the Iowa Department of Transportation, Iowa State University, and the Soy Transportation Coalition. Together, those entities provided funding to load-test three rural bridges that had been assigned load restrictions in Sioux County, Ida County, and Johnson County. Steenhoek says that project successfully provided a more accurate assessment of the bridges and in fact resulted in removal of the load restrictions.
Currenlty, bridges are inspected visually, which Steenhoek says is less accurate than Iowa State?s methods. He belives using sensors will take some of the guesswork out of prioritzing bridges for funding and maintenance.
?What we want to do with the bridge engineering center at Iowa State University is have the funding to test rural bridges,? he explains, ?so that you remove a lot of the subjectivity out of evaluating bridges. So that you know, if a bridge is in exquisite condition, the technology will validate that. If it?s in mediocre condition, the technology will validate that. If it?s in poor condition, the technology will validate that. And what that results in is better decision-making.?
That state funding could become available as early as late June or early July. If funding is secured, Steenhoek says testing would begin immediately.
