About PlainBridge

Our Mission

PlainBridge exists because the structural health of America's bridges should be easy for every driver, commuter, and taxpayer to check — without navigating federal spreadsheets or paying for proprietary infrastructure databases.

We believe that bridge safety data collected at public expense belongs to the public in a form they can actually use. The Federal Highway Administration maintains the National Bridge Inventory with detailed condition data on every public highway bridge in America. PlainBridge makes this data searchable, browsable, and understandable for non-engineers.

Our goal is infrastructure transparency. When you cross a bridge every day, you should be able to check its condition rating, see when it was last inspected, and understand what "structurally deficient" actually means in practical terms.

Our Data Sources

Federal Highway Administration (FHWA) — National Bridge Inventory (NBI)

All bridge data on PlainBridge comes from the National Bridge Inventory, the federal database mandated by Congress since 1968 following the catastrophic Silver Bridge collapse in Point Pleasant, West Virginia. The NBI is the most comprehensive bridge condition database in the world, covering 575,000+ structures.

The NBI includes condition ratings (deck, superstructure, substructure on a 0-9 scale), sufficiency ratings (0-100 composite score), structural deficiency status, year built, material type, span count, average daily traffic, and geographic coordinates for every public highway bridge.

Official source: FHWA National Bridge Inventory.

How We Process the Data

We download the annual NBI dataset from FHWA and process it through our ETL pipeline:

  • Parsing: NBI data arrives as fixed-width text files with one file per state. We parse each record into structured fields following the FHWA Recording and Coding Guide.
  • Condition classification: We apply FHWA's official classification standards to categorize bridges as Good, Fair, Poor, or Structurally Deficient based on their condition ratings.
  • Geographic organization: Bridges are organized by state and county for browsable navigation, with coordinates for precise location reference.
  • Statistics computation: We calculate state-level and county-level aggregations including deficiency rates, average age, condition distributions, and maintenance priority indicators.

No data is modified, interpolated, or editorialized. Condition categories follow FHWA's official classification standards exactly.

Data Currency

PlainBridge currently displays the 2024 National Bridge Inventory data release. FHWA releases updated NBI data annually, typically in the spring covering the prior calendar year. States are required to submit inspection data every two years per bridge, though many conduct annual inspections.

Bridge condition can change between inspection cycles due to weather events, traffic loads, or maintenance work. The NBI reflects the most recent inspection data submitted by each state. We update PlainBridge when new annual data becomes available from FHWA.

Editorial Independence

Content on PlainBridges is compiled by our editorial team. Raw data from the FHWA National Bridge Inventory is transformed into readable profiles by our continuous editorial pipeline, validated against the source before publication. The PlainBridges editorial team, operating under Kiznis Studio, is responsible for editorial standards, methodology, and corrections.

We do not accept payment, sponsorship, or promoted placement from manufacturers, operators, or any transportation/product entity. Our only revenue source is contextual display advertising served by Google AdSense — advertisers do not influence which entities we cover or how we present data, and they do not receive preferential placement.

Limitations & Disclaimers

PlainBridge is an informational resource, not an engineering assessment tool:

  • Not real-time: NBI data reflects the most recent inspection, which may be up to 24 months old. Current conditions may differ from what is shown.
  • "Structurally deficient" is not "unsafe": The SD designation means a bridge needs repair or monitoring, not that it is dangerous to cross. SD bridges remain open to traffic and are inspected more frequently.
  • Inspection subjectivity: Condition ratings involve professional judgment and may vary between inspectors. A bridge rated 5 by one inspector might be rated 4 or 6 by another.

PlainBridge is not affiliated with FHWA, the U.S. Department of Transportation, or any government agency. We are an independent data portal presenting public information in a more accessible format. For safety concerns about a specific bridge, contact your state Department of Transportation.

Contact

Questions or feedback? Email hello@plainbridges.com.

PlainBridge is published by ", a data intelligence company that builds free, public-interest data portals.