bridge spans Blue Creek

A bridge spans Blue Creek in Linn County near Center Point, Iowa. According to the American Road and Transportation Builders Association, this is a structurally deficient bridge.

This is not a contest anyone wants to win, but Iowa ended up in first place.

A bridge profile report from the American Road and Transportation Builders Association in March said Iowa had the most structurally deficient bridges in America, with 4,675. That is nearly a thousand more than second place Pennsylvania, which had 3,770.

The 4,675 bridges represents 19.4% of bridges in the state, according to the report, which puts Iowa third in total percentage of bridges.

However, these numbers appear to be an improvement, with plans to continue lowering those numbers in the state.

Iowa Department of Transportation Bridge Maintenance and Inspection Engineer Scott Neubauer said things have been steadily improving over the years, especially on the state highway system.

The Iowa DOT uses its own rating system, declaring conditions as good, fair or poor. In 2008, nearly 250 state highway bridges were deemed to be in poor condition, but more than 10 years later, that number has been reduced to 43, according to information from the DOT.

While there has been a significant decrease in state highway deficiencies, more than 90% of the roads cited by the ARTBA report were considered rural and would not fit under state oversight.

Neubauer said the DOT does not work on bridges on county and city roads, with each local government being responsible for their areas. That leaves them to decide how to use the money allocated from the road use tax fund.

Brad Ketels, engineer for Linn County, said his area is “pretty fortunate” with bridges, due to the work of his predecessor, Steve Gannon.

“He was a structural engineer, so bridges were one of his things,” Ketels said. “Back in the ’70s, he put together a bridge management plan for Linn County. Basically, we have X number of bridges, a bridge lasts this long, this is how many bridges we need to replace each year to keep up.”

He said some Iowa counties are not taking the same approach, which leads to more structurally deficient bridges. Ketels said of the 254 bridges in his county, only 11 (4.3%) are considered in poor condition, compared to the statewide average of nearly 23.3%.

With the implementation of the 2015 10-cent gas tax, Neubauer said the extra monies allowed them to work at a faster rate than their five-year plan had projected.

“What it did was help us move some of those projects forward,” he said. “We didn’t necessarily create new projects, but the best thing we could do was pull projects already in our program ahead a few years to utilize the extra money we were receiving.”

He said on average they are receiving $220 million per year from the gas tax, and about $100-105 million of that goes to the state highway system. There is no specific amount dedicated to bridges, Neubauer said, with funding going where it is most needed.

“We don’t necessarily distribute money evenly over the state. We do things as needed and most appropriate,” he said. “We meet annually with each of our districts and look at what the needs are in our district and prioritize the structures that are in need of repair. Then we put our list together.”

Ketels said the federal Highway Bridge Program helps fund much of the work they do in Linn County.

The program is intended to use a portion of the federal funds set aside from the Surface Transportation Block Grant Program for “the replacement or rehabilitation of structurally deficient or functionally obsolete public roadway bridges,” according to the Iowa DOT.

The HBP is projected to give out just under $36.2 million to Iowa counties in 2019, with a three-year total of $105.5 million dating back to 2017. That averages out to more than $1 million each for the 99 counties over a three-year span.

Ketels said a bridge can typically last 75 years before being replaced, but maintenance will be needed during that span.

The driving surface is usually the first part of the bridge that starts to deteriorate, Neubauer said, leading to poor ratings. He said maintaining the surface, or deck, is the most beneficial item to keeping a bridge in service.

Ketels said the county revises its five-year plan every year so it can plan ahead on bridge construction. However, he said just because something is in the five-year plan, it might take longer than five years to address.

“Mostly now we are replacing bridges,” Ketels said. “We did a few smaller rehabs in the last couple of years, but now we are hoping to replace one or two per year. This year we just have one project.”

The average daily traffic on half of the poor bridges on the list is less than 35 vehicles per day, Neubauer said. It might not be top priority to spend a lot of money on bridges that do not see many travelers, so counties tend to maintain as best they can, he added.

“It’s a continuing process all the time of doing replacements when needed,” Neubauer said. “I’m not as familiar with the local agencies, but we (at the state level) have been increasing the amount we’ve been spending on bridges over the last few years and getting a good handle on keeping our bridges in the best condition we can.”

Sign up for our weekly CropWatch newsletter

* I understand and agree that registration on or use of this site constitutes agreement to its user agreement and privacy policy.