Mapping the Sorry State of America's Bridges

About 10 percent of America’s 600,000 bridges are structurally deficient, requiring “significant maintenance, rehabilitation or replacement,” according to a 2013 report by Transportation for America. Many of them have exceeded their intended lifespan by more than a decade, and yet Americans continue to use them, taking 260 million trips over deficient bridges on a daily basis. Alarming stuff, especially now that the cartographer and GIS consultant Jonah Adkins offers us a new opportunity to stare down this data on a map.

In the new dot map Bridges of America, Adkins lays out the sorry facts of the Federal Highway Administration’s National Bridge Inventory, which accounts for data on bridge type, structural conditions, average daily traffic, and more, going back to 1992. You can zoom and explore the country’s bridgespans and viaducts by their daily traffic count or by their condition: “Ok,” “Structurally Deficient,” or “Functionally Obsolete.” (There are other types of labels that the FHA gives to bridges, but Adkins says he settled on the three that were easiest to understand.)