About 185 million times a day, vehicles cross nearly 56,000 U.S. bridges in need of repair, according to a new study from the American Road and Transportation Builders Association (ARTBA).

Which states have the most problems? Around 20 percent of the bridges in Iowa and Pennsylvania are structurally deficient [PDF]. In Oklahoma, which ranks third, 15 percent of the bridges have structural problems.

But the scope of the problem is bigger than any individual state, said ARTBA Chief Economist Dr. Alison Premo Black, who conducted the analysis.

“The report’s key takeaway and the most important thing to focus on is that 1,900 bridges on the National Highway Freight Network [the interstate highway system] are structurally deficient,” Black said in a story published on ARTBA’s Washington Newsline website. “That’s America’s economic expressway.  Bridge failures or restrictions on that 66,000-mile network should not be an option.”

The association compiled the report from the U.S. Department of Transportation’s 2016 National Bridge Inventory database, which includes slightly fewer deficient bridges than were logged in 2015 (down 0.5 percent), ARTBA noted in a press release. The bridges in the inventory “may not be imminently unsafe, [but] they are in need of attention,” the group said.

In addition to state-by-state rankings, the report includes a list of the top 250 deficient bridges in the U.S. and the top 10 in each state. Other findings:

• 13,000 interstate bridges need replacement, widening, or major reconstruction.
• The average age of a structurally deficient bridge is 67 years old, compared to 39 years for nondeficient bridges.
• 28 percent of U.S. bridges are over 50 years old and have not had major reconstruction work.

“America’s highway network is woefully underperforming. It is outdated, overused, underfunded, and in desperate need of modernization,” Black said. “State and local transportation departments haven’t been provided the resources to keep pace with the nation’s bridge needs.”

The Federal Highway Administration estimates bridge repairs will require $20.5 billion a year over the next 16 years, according to the Washington Post.

“Those bridges and the freight network overall should be the focal point of any new federal infrastructure initiative that emerges,” Black said.

During last year’s presidential campaign, then-candidate Donald Trump promised to invest heavily in U.S. infrastructure. According to January news reports, the Trump administration has identified about 50 priority infrastructure projects, including bridge repairs, but an infrastructure funding bill may not come till next year, Axios reported this week.

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