America's bridge infrastructure — long seen as dysfunctional — has been steadily improving for the last 20 years.

Why it matters: The amount of bridges rated poor, or an equivalent metric, by the federal government's bridge inventory has fallen from 15% in 2000 to 6.8% in 2023.

Zoom in: More than 1,200 bridges across the U.S. have been rated in poor condition for more than 5 years, according to the federal government's national inventory.

• Over half of those 1,200 bridges have been rated "poor" for more than 10 years.
• The longer a bridge sits in poor condition without repairs, the more it risks falling into serious or critical condition, where collapse becomes a risk.

The big picture: In 2023, the U.S. recorded 42,000 bridges in poor condition — 6.8% of all bridges in the country.

• The Department of Transportation estimates it would cost over $276 billion to repair all of these bridges.
• But if we focus on only the most neglected bridges — those in poor condition for more than 5 years — the cost of repairs falls to $4.6 billion.

By the numbers: Pennsylvania, New York and Michigan collectively house 40% of the neglected bridges, while areas of the upper midwest and southwest fare much better.

• One factor is the age of bridges. Pennsylvania, which tops the list of neglected bridges, has nearly 2,000 bridges that were built over 100 years ago.
• Texas, which has a single neglected bridge, has just 311 bridges built over 100 years ago.

Between the lines: The bipartisan infrastructure law, signed in 2021, sets aside $40 billion to further repair and rebuild the nation's bridges.

• That investment, however, will take years to go from ink to concrete.

How it works: A bridge being in "poor" condition does not mean it is at risk of imminent collapse. The National Bridge Inventory has three grades below poor that indicate structural issues may necessitate bridge closures.

• Few bridges are currently rated in "serious" or "critical" condition. Bridges that reach those levels are typically fixed or closed.
• The Department of Transportation did not respond to a request for comment on this story.