What It Means
A bridge is classified as structurally deficient when its deck, superstructure, or substructure receives a condition rating of 4 (Poor) or below. This does not mean the bridge is unsafe or likely to collapse — it means the bridge needs significant repair, rehabilitation, or replacement. Structurally deficient bridges are still open to traffic and are inspected more frequently. As of 2025, approximately 7.5% of U.S. bridges are structurally deficient.
Frequently Asked Questions
What does "Structurally Deficient" mean?
A federal classification for bridges where any major component is rated 4 or below on the 0-9 NBI scale.
Why does Structurally Deficient matter for bridge safety?
A bridge is classified as structurally deficient when its deck, superstructure, or substructure receives a condition rating of 4 (Poor) or below. This does not mean the bridge is unsafe or likely to collapse — it means the bridge needs significant repair, rehabilitation, or replacement. Structurally...