There are more than 617,000 bridges across the United States. Currently, 42% of all bridges are at least 50 years old, and 46,154, or 7.5% of the nation’s bridges, are considered structurally deficient, meaning they are in “poor” condition. Unfortunately, 178 million trips are taken across these structurally deficient bridges every day. In recent years, though, as the average age of America’s bridges increases to 44 years, the number of structurally deficient bridges has continued to decline; however, the rate of improvements has slowed. A recent estimate for the nation’s backlog of bridge repair needs is $125 billion. We need to increase spending on bridge rehabilitation from $14.4 billion annually to $22.7 billion annually, or by 58%, if we are to improve the condition. At the current rate of investment, it will take until 2071 to make all of the repairs that are currently necessary, and the additional deterioration over the next 50 years will become overwhelming. The nation needs a systematic program for bridge preservation like that embraced by many states, whereby existing deterioration is prioritized and the focus is on preventive maintenance. [ x ]

The American Society of Civil Engineers (ASCE) has compiled regular “report cards” on the state of U.S. infrastructure since the 1980s. In its 2021 report [PDF], the ASCE found that the nation’s infrastructure averaged a “C-,” up from a “D+” in 2017 and the highest grade in twenty years. Still, the group estimated that there is an “infrastructure investment gap” of nearly $2.6 trillion this decade that, if unaddressed, could cost the United States $10 trillion in lost GDP by 2039. [ x ]

They also don't tell ya, but most of the non-defense infrastructure is owned by the private sector , and that includes some bridges too, which makes it harder to just pour govt money directly to fix these things, it has to go via different tax incentive routes etc.