Almost 56,000 U.S. bridges are 'structurally deficient.' Is one near you on the list?

According to the study, one quarter of the bridges listed are at least 50 years old, and have never undergone any reconstruction.

Bridges that have been labeled structurally deficient aren't necessarily in immediate danger of collapse, the study pointed out. The term “structurally deficient” means that the bridges need rehabilitation or replacement because at least one major component has deteriorated or because the bridge has other problems.

The study listed problem bridges in every state. Iowa has the largest number of structurally deficient bridges at nearly 5,000. The top 14 most-traveled deficient bridges are located in California.