A study suggests that weight limits on rural bridges in parts of the U.S. may be too low, limiting transportation options for farm equipment or grain loads.

A rural bridge in Renwick, Iowa. Source: WikiA bridge testing method put forward by Iowa State University’s Bridge Engineering Center involves attaching sensors to strategic points on a bridge. Researchers say the method may help remove unnecessary weight restrictions from rural bridges, and help county road maintenance departments determine which structures need repairs the most.

Researchers tested three rural bridges, all of which had their load limits lifted as a result. With nearly three-quarters of the nation's 607,380 bridges in rural areas, similar outcomes in other states could make a big impact on farmers. The research team says it will work in other states to test more rural bridges.