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Iowa DOT Hopes Infrastructure Plan Will Help Structurally Deficient Bridges

AMES, Iowa  --  President Donald Trump is giving his State of the Union Address on Tuesday, and part of it will focus on a $1.5 trillion infrastructure plan.

A recent report from the American Road and Transportation Builders Association shows there are more than 50,000 bridges in need of repair across the United States. Here in Iowa, 5,067 bridges are labeled structurally deficient; that means at least one of the three key elements of a bridge are in poor or worse condition.

“We inspect all of our bridges every 24 months. Every 24 months, we rate several portions of that bridge and there’s three main portions of every bridge: there’s the deck or the driving surface, that you drive your car on, there’s what we call the super structure, normally the girders underneath that deck that holds that up, and then there’s the substructure, which are the piers normally that hold the superstructure up. And any one of those three things are given a rating, and if the ratings get to a certain level on one of those three the bridge is considered structurally deficient,” Iowa DOT Bridge Maintenance and Inspection Engineer Scott Neubauer said.

Some structurally deficient bridges are still safe to drive on and have a weight restriction.

“We have a requirement that if a bridge can no longer carry three tons of load, that the bridge has to be closed. And of those 5,000 structurally deficient bridges we have here in Iowa, there are 500 closed right now and safety is a very important factor in our decisions,” Neubauer said.

Neubauer said the bridges with the most issues were built before 1980.

“Since the early 80s was when we modified some of our designs for bridges. We use different materials, higher strength material, materials that are meant to withstand some of the corrosive environments that our bridges are in. So the bridges built from 1980 until today are built to a higher standard than they were prior to that,” he said.

The Iowa DOT is responsible for making sure cities and counties inspect their bridges on time, but how they maintain their bridges is up to them.

“The funding is their biggest hurdle. They have a limited amount of money that they deal with and they have bridges that have very low traffic volumes. A lot of these structurally deficient bridges have traffic volumes below 35 vehicles a day. And to spend hundreds of thousands or even millions of dollars on something that doesn’t carry that much traffic is just really hard for them to justify,” Neubauer said.

Neubauer said it’s important to make the repairs now so roads and bridges are better for the future.

“Now because it’s crumbling doesn’t mean it’s unsafe, it’s just getting to the point where we need to start doing things to keep it ready for the future."