Microproduct data guideintermediate

FHWA National Bridge Inventory

Annual inspection records for U.S. highway bridges for building deficient-bridge maps and local infrastructure scorecards.

Start the guide Open official source

At a glance

Difficulty
Intermediate — some data preparation helps
Size
Small · 0.001–0.1 GB
Formats
CSV, Text
Access
Download
API key
Not required
Provider
Federal Highway Administration
Updates
Annual
Data terms
U.S. Government public data / federal copyright guidance

From source to product signal

Test a product idea in four steps

FHWA publishes annual National Bridge Inventory extracts as delimited state files. Start with one small jurisdiction and the documented field format. Inspection ratings are not a live closure feed, and the yearly filename changes with each inventory.

1

Check the setup

  • Python 3.10 or newer
  • A notebook environment such as Jupyter or Google Colab
  • An internet connection
2

Access the data

  1. 1.Open the current-year NBI ASCII download page and choose a comma-delimited state file.
  2. 2.Read the record-format notes before assigning column names.
  3. 3.Filter to highway bridges and keep condition ratings with the retrieval year.
Open official source
3

Run the Python example

Install the packages, then run the notebook cell.

python -m pip install pandas

import pandas as pd

bridges = pd.read_csv(
    "https://www.fhwa.dot.gov/bridge/nbi/2025/delimited/DC25.txt",
    dtype=str,
    quotechar="'",
)
bridges["retrieved_at_utc"] = pd.Timestamp.now(tz="UTC")
print(bridges.head())
4

Test a useful signal

Rank one jurisdiction's bridges by deck condition

Test whether annual inspection ratings can support a local infrastructure watch list.

  1. 01Identify the deck, superstructure, and substructure rating fields from the format guide.
  2. 02Count bridges in poor condition and map them when coordinates are present.
  3. 03State that ratings are inspection snapshots, not current closures, and that coding-guide definitions changed over time.

Dataset details

Federal Highway Administration is a government source. Last verified 2026-08-17. Temporal coverage: annual inventories submitted each spring.

Theme

Geospatial & Infrastructure

Domains

InfrastructureTransportationPublic Safety

Data types

TabularGeospatial

Tasks

Risk MappingGeographic AnalysisBenchmarking

Geography

United States

Formats

CSVText

Provider

Federal Highway Administration

Data terms

U.S. Government public data / federal copyright guidance