Bridges — FHWA National Bridge Inventory: Condition, Posting & Clearance

Search US bridges in the FHWA National Bridge Inventory. Scope with state, county (3-digit FIPS code), and/or condition (Good/Fair/Poor); optional filters: posting_status (open/posted/closed/not_yet_open), owner_code, scour_critical, year_min/year_max, min_adt, route, and q (text match on facility carried, feature crossed, location). Returns decoded records with condition rollup, posting status, clearances, and labels. Read-only lookup of the FHWA NBI 2025 annual snapshot; no API key. limit defaults to 100 (max 1000); offset defaults to 0, pass offset in multiples of limit to page. Use find_bridges_nearby instead for radius queries around a point, get_worst_bridges instead for Poor-condition lists, and list_bridges_in_county instead for all bridges in one county.

Get one bridge by its FHWA structure number (Item 8). Structure numbers are unique within a state; pass state to be exact. Returns the full decoded record. Read-only; no API key. If no bridge matches, the call errors; if state is omitted and the number matches in more than one state, the call errors, pass state to be exact. Use search_bridges instead for fuzzy or name-based lookups.

List bridges in one county (state + 3-digit FIPS county code), paged. Read-only lookup of the FHWA NBI 2025 annual snapshot; no API key. Results are decoded records ordered by state, county code, then structure number. limit defaults to 100 (max 1000); offset defaults to 0, pass offset in multiples of limit to page. Use search_bridges instead for filtered queries across counties, and get_county_summaries instead for county counts rather than individual bridges.

The worst-rated bridges in a state (condition = Poor), ordered by lowest component rating then age. Each result is a full decoded bridge record (component condition ratings, year built, location, posting status). State is required. Use for 'worst bridges in X' questions. Read-only; no API key. limit defaults to 50 (max 500) and controls how many worst bridges are returned. Use list_posted_or_closed_bridges instead for posted/closed bridges, and search_bridges instead for filtered queries.

Bridges in a state that are load-posted or closed to traffic (NBI Item 41 status P/R/K), worst condition first. Relevant for routing and heavy-haul feasibility, but per FHWA, NBI data must not be used as the sole source for route clearance; inspections can be up to ~24 months old. Read-only; no API key. limit defaults to 100 (max 1000); offset defaults to 0. Use get_worst_bridges instead for Poor-condition bridges regardless of posting status, and search_bridges instead for a narrower filter set.

Bridges in a state whose vertical clearance is at or below max_height_m (or max_height_ft in feet, pass one, not both). Default clearance is over the roadway on the bridge (NBI Item 10); set under=true for the clearance under the bridge (Item 54B), which is what matters for routes passing beneath. Sentinel 'no restriction' values are excluded. Read-only; no API key. limit defaults to 100 (max 500). Use screen_corridor instead when you have a full vehicle profile, not just a height threshold.

Bridge summary for one state: total bridges, counts by condition (Good/Fair/Poor), posted and closed counts, scour-critical count, average year built, total deck area. Without a state, returns per-state totals with condition counts for all states. Read-only; no API key. Data is the FHWA NBI 2025 annual snapshot. Use get_county_summaries instead for the per-county breakdown within a state, list_posted_or_closed_bridges or get_worst_bridges for bridge-level problem lists, and search_bridges for individual bridge records.

Per-county bridge counts for a state, with Poor-condition and posted/closed counts per county. Read-only; no API key. Returns one row per county present in the state data. Use get_state_summary instead for a statewide rollup, and list_bridges_in_county instead for individual bridges in one county.

Bridges near a point, nearest first. Pass lat/lon in decimal degrees; radius_km defaults to 10 (max 500). Each returned bridge carries distance_km. Bridges with no coordinates are excluded. Unlike the state-scoped tools, this one takes no state, the point is the scope. Read-only; no API key. limit defaults to 100 (max 1000). Use screen_corridor instead when the query is a route polyline rather than a point, and search_bridges instead when you need state, county, or condition filters rather than distance.

Screen a corridor for a vehicle profile: pass a route polyline as points (array of {lat, lon} objects tracing the actual road — submit a real route trace, not city points) plus a vehicle height and weight, and get back every bridge near the corridor that fails the profile, fails first then warnings, each nearest first with distance_km. Read-only: it checks data, it changes nothing. Height: pass one of height_ft or height_m. Weight: pass one of weight_lbs or weight_t (compared against the bridge operating rating in metric tons). buffer_km defaults to 2 (max 25) and sets how far from the polyline a bridge counts. pad_ft/pad_m (default 6 in) is added to the height before the clearance test. Fails: clearance below height plus pad (under-bridge clearance), posted below weight, closed, not yet open. Warnings, not failures: poor condition, unknown rating, unknown clearance. limit defaults to 100 (max 500); fails come first, warnings fill the remainder. Returns fails and warns arrays with fail_count and warn_count totals. Use this instead of find_bridges_nearby when you have a corridor, not a point, and instead of find_low_clearance_bridges when you have a full vehicle profile, not just a height threshold. This is a buffered-polyline screen, not a router: it does not produce directions. Data is the FHWA NBI 2025 annual snapshot, not live status, and bridges with no coordinates are excluded.