Interactive · FHWA NBI

Bridge data tools

Three free tools built directly on the National Bridge Inventory — look up any structure, compare two states, or decode a condition rating into plain English.

575,638
Bridges searchable
52
States & territories
6.1%
Structurally deficient

Bridge lookup

Search 575,000+ bridges by route, waterway, or place and open the full NBI record.

State comparison

Put two states side by side on condition share, structural deficiency, and inventory size.

Condition decoder

Enter deck, superstructure, and substructure ratings to see how FHWA classifies a bridge.

States with the highest deficiency rate

A quick read on where the structural-deficiency problem concentrates — explore any of them in the state comparison tool.

Top 8 states by structurally deficient rate

Share of each state's inventory flagged structurally deficient (states with 1,000+ bridges)

% structurally deficient

What this shows Iowa leads at 20.01% structurally deficient — well above the 6.1% national rate.

Source FHWA National Bridge Inventory As of 2024 NBI release

How do these bridge tools work?

Where does the data come from?

Every result is queried live from the Federal Highway Administration's National Bridge Inventory — the federal database that catalogs every public highway bridge. Nothing is estimated or fabricated.

Are the tools free?

Yes. All three tools are free and ad-supported, and they run on public-domain U.S. government data you are free to reuse.

Does a structurally deficient bridge mean it is unsafe?

No. A structurally deficient classification is a repair-priority flag, not a closure order. The condition decoder explains exactly which rating triggers it.

Explore more

State condition rankings Browse every state Largest state inventories How safety ratings work Structurally deficient bridges Data methodology