About BridgeStats
What is BridgeStats?
BridgeStats makes U.S. bridge infrastructure data accessible and understandable. We transform raw federal inspection data into clear condition ratings, grades, and statistics for every bridge in the country -- over 620,000 structures across all 50 states, the District of Columbia, and U.S. territories.
Whether you are a journalist researching infrastructure stories, an engineer evaluating regional conditions, a policy analyst comparing states, or a curious citizen who wants to know the condition of the bridge you cross every day, BridgeStats puts the data at your fingertips.
Data Sources
National Bridge Inventory (NBI)
Our primary data source. The NBI is maintained by the Federal Highway Administration (FHWA) and contains detailed inspection data for every bridge on public roads in the United States. State and federal inspectors evaluate each bridge at least once every two years, recording condition ratings for deck, superstructure, substructure, and culvert components on a 0-9 scale.
Census FIPS Codes
We use U.S. Census Bureau FIPS (Federal Information Processing Standards) codes to accurately map bridges to their states and counties, ensuring consistent geographic classification across all data.
Federal Highway Administration (FHWA)
The FHWA, part of the U.S. Department of Transportation, oversees the NBI program and defines the standards by which all bridges are inspected and rated. Their Bridge Inspector's Reference Manual governs the inspection methodology nationwide.
State Grading Methodology
BridgeStats assigns each state a letter grade based on a weighted score that combines two key metrics:
- Poor Condition Rate (60% weight): The percentage of bridges classified as structurally deficient or in poor condition. A lower percentage yields a higher score. The formula:
max(0, 100 - poorPct * 5). - Average Sufficiency Rating (40% weight): The FHWA's composite sufficiency rating (0-100) that factors in structural adequacy, serviceability, and essentiality for public use.
| Grade | Weighted Score | Interpretation |
|---|---|---|
| A | 90 - 100 | Excellent infrastructure with very few bridges in poor condition |
| B | 80 - 89 | Good condition overall with a manageable number of deficient bridges |
| C | 70 - 79 | Average condition with notable infrastructure concerns |
| D | 60 - 69 | Below average with a significant share of bridges needing attention |
| F | Below 60 | Critical infrastructure concerns requiring urgent investment |
NBI Condition Ratings Explained
Each bridge component (deck, superstructure, substructure, or culvert) is rated on a 0-9 scale during inspections:
| Rating | Condition |
|---|---|
| 9 | Excellent |
| 8 | Very Good |
| 7 | Good |
| 6 | Satisfactory |
| 5 | Fair |
| 4 | Poor |
| 3 | Serious |
| 2 | Critical |
| 1 | Imminent Failure |
| 0 | Failed |
A bridge is classified as "poor condition" when any of its primary components receives a rating of 4 or below.
Disclaimer
BridgeStats is an independent project and is not affiliated with the Federal Highway Administration, the U.S. Department of Transportation, or any government agency. All data is sourced from publicly available federal datasets and is provided strictly for informational purposes only.
Bridge condition data reflects the most recent NBI data release and may not capture repairs, deterioration, or changes that have occurred since the last inspection cycle. Conditions can change between inspection periods.
For official bridge condition information, safety concerns, or to report a bridge issue, please contact your state Department of Transportation or visit the FHWA website.