Power, Water & Bridges

Michigan Bridge Conditions — NBI Ratings

Name: Michigan Bridge Conditions — NBI Ratings
Creator: FHWA National Bridge Inventory (NBI)
License: https://www.usa.gov/government-works

Source: FHWA National Bridge Inventory (NBI)

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Bridge Conditions for Michigan, latest reading.

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What this means

The NBI catalogs every public-road bridge in the U.S. Each gets condition ratings (0–9) for deck, superstructure, and substructure. "Poor" means at least one component is rated 4 or below; "Structurally Deficient" is a stricter federal subset that triggers funding eligibility.

What you can do

Michigan has ~11,000 bridges; roughly 7% are rated Poor at any given time.
Funding for bridge replacement comes from the federal Bridge Investment Program — see FHWA grants.
For commuter route planning, MDOT publishes weight-restricted bridges (problem for RVs / trailers).