Every Bridge Near You Has a Safety Rating
Data source: ZipCheckup analysis of FHWA National Bridge Inventory (NBI) 2024
The federal government inspects every bridge in America at least once every two years. The results go into a database. The database is public. And the picture it paints is sobering.
It's called the National Bridge Inventory — and ZipCheckup has mapped the data to your ZIP code.
The Scale of What's Tracked
The NBI covers bridge infrastructure across 42,675 ZIP codes. Every bridge longer than 20 feet in the country gets a condition rating on a 0–9 scale for three components: deck, superstructure, and substructure. A rating of 4 or below means "poor condition" — structurally deficient.
The weighted average age of bridges in the dataset is 48.6 years. Nearly 5,000 ZIP codes have an average bridge age of 60 years or older. In 589 ZIPs, the average bridge has been standing for more than 70 years.
These structures were designed for the traffic loads of the 1960s and 1970s. They're carrying the traffic loads of 2026.
The Worst ZIP Codes
Some areas carry a dramatically higher share of deteriorating infrastructure. Among ZIP codes with at least 20 bridges, the worst performers are concentrated in Iowa's rural counties:
| ZIP Code | Bridges | Deficient | Avg Age | Risk Level |
|---|---|---|---|---|
| 50839 | 185 | 45.9% | 58 yrs | High |
| 50005 | 303 | 42.9% | 56 yrs | High |
| 50051 | 303 | 42.9% | 56 yrs | High |
| 50158 | 303 | 42.9% | 56 yrs | High |
| 50234 | 303 | 42.9% | 56 yrs | High |
Iowa appears repeatedly — its county-level bridge networks are aging faster than replacement budgets can keep up. But the problem isn't limited to rural America. Houston-area ZIP codes (770xx) have the highest raw bridge counts — over 4,000 bridges per ZIP cluster — where even a low deficiency rate of 0.6% still represents dozens of bridges in poor condition.
The Risk Map
ZipCheckup assigns a bridge infrastructure risk level to each ZIP code based on deficiency rates, bridge age, and worst individual ratings:
| Risk Level | ZIP Codes | Share |
|---|---|---|
| High | 4,029 | 9.4% |
| Elevated | 10,088 | 23.6% |
| Moderate | 15,321 | 35.9% |
| Low | 13,206 | 30.9% |
One in three ZIP codes has elevated or high bridge infrastructure risk. That means the bridges in your area may have significant structural deterioration, advanced age, or both.
Why Bridge Age Matters
Bridges aren't designed to last forever. Most reinforced concrete bridges have a design life of 50–75 years. Steel bridges can last longer with maintenance, but corrosion, fatigue cracking, and increased traffic loads take their toll.
The national weighted average of 48.6 years means the country is approaching the point where large numbers of bridges will simultaneously reach end-of-life. The American Society of Civil Engineers estimates the backlog of bridge repair needs at over $125 billion.
Older bridges also tend to have lower weight limits, narrower lanes, and design features that don't meet modern safety standards. A bridge built in 1965 wasn't designed for 80,000-pound trucks.
What This Means for Your Safety
A structurally deficient rating doesn't mean a bridge will collapse tomorrow. It means the bridge has deteriorated enough to require monitoring, load restrictions, or scheduled replacement. But the I-35W bridge collapse in Minneapolis (2007) and the Fern Hollow Bridge collapse in Pittsburgh (2022) both involved bridges that had been flagged in NBI data before they failed.
The data exists. The inspections happen. The question is whether the repairs follow.
How to Check Your ZIP Code
Every ZIP code in our database includes bridge infrastructure data as part of its safety report. You can see:
- How many bridges are in or near your ZIP
- What percentage are structurally deficient
- The average age of bridges in your area
- Your ZIP's bridge infrastructure risk level
- How your area compares nationally
Methodology: ZipCheckup analyzes Federal Highway Administration National Bridge Inventory (NBI) data for 42,675 ZIP codes. Bridge condition ratings follow NBI standards (0–9 scale). Structurally deficient bridges are those with any component rated 4 or below. Risk levels are calculated from deficiency percentages, average age, and worst individual bridge ratings. All data reflects the most recent NBI inspection cycle.
Frequently Asked Questions
What is the National Bridge Inventory?
The NBI is a federal database maintained by the Federal Highway Administration (FHWA) that contains detailed information on every bridge in the United States over 20 feet long. Each bridge receives condition ratings for its deck, superstructure, and substructure on a 0–9 scale. Bridges rated 4 or below are classified as structurally deficient.
How many bridges are tracked?
Our dataset covers 42,675 ZIP codes with bridge infrastructure data. Nationally, over 600,000 bridges are cataloged. Among ZIP codes with 20 or more bridges, the worst have over 40% rated structurally deficient.
What does 'structurally deficient' mean?
A structurally deficient bridge has at least one component — deck, superstructure, or substructure — rated in poor condition (4 or below on the 0–9 NBI scale). It doesn't necessarily mean the bridge is unsafe to cross, but it does mean the bridge has deteriorated to the point where it needs repair or replacement.
Can I check bridge conditions near my ZIP code?
Yes. Enter your ZIP code on ZipCheckup to see your full infrastructure report, including bridge conditions, deficiency rates, and risk ratings.