For an advanced industrial country, America has pretty lousy infrastructure. Our ports, airports, roads and transit regularly get ‘D’ and ‘C’ grades in the the American Society of Engineers’s report cards . As in: Could do a lot better.

About 11% of the nation’s 600,000 bridges are “structurally deficient,” meaning they need significant repair or rehabilitation. You can see them all visualized on this map created by Jonah Adkins. It shows both bridge status (“structurally deficient” in orange, “functionally obsolete” in red) and traffic counts across bridges (75,000 a day in dark orange, 100,000-plus in red).

Functionally obsolete doesn’t necessarily mean the bridge is dangerous. It means it’s “not suitable for its current use” probably because it hasn’t been updated. “It’s like a house that was built in the 1920s. It’s not necessarily made up to today’s standards and could probably use some work but it won’t stop you from living in it,” Adkins says.

Some of the oldest bridges in the country are in the corridor going west from Philadelphia to Pittsburgh, Columbus, Ohio, and St. Louis. Fully 20% of bridges in Pittsburgh, for instance, are structurally deficient. That is, 5 million people a day drive over a structure that engineers aren’t happy with.

“A lot of bridges weren’t made for the types of vehicle load they’re having to carry,” Adkins say. “That doesn’t mean it’s going to fall down any minute, but it’s definitely aging infrastructure.”

Cover Photo: Tupungato via Shutterstock