---
license: cc-by-4.0
language:
  - en
tags:
  - bridge
  - infrastructure
  - national-bridge-inventory
  - fhwa
  - deterioration
  - civil-engineering
  - united-states
  - nbi
pretty_name: Bridgedeck — National Bridge Inventory (2000–2023)
size_categories:
  - 1M<n<10M
---

# Bridgedeck — National Bridge Inventory (2000–2023)

Part of the **bridgedeck** dataset collection for US bridge deck deterioration research.

## Overview

Cleaned and parsed National Bridge Inventory (NBI) records for all US states,
2000–2023. One row per bridge per inspection year. Covers structural properties,
geometry, materials, traffic, condition ratings, and a derived 5-year deck
deterioration target.

The NBI is the backbone of the bridgedeck dataset — all other datasets
(PRISM, NOAA, NSHM, NFHL, Salt) are joined to it via `bridge_id` or `county_fips`.

## Source

**Source:** [FHWA National Bridge Inventory](https://www.fhwa.dot.gov/bridge/nbi/ascii.cfm)

**Coverage:** All 50 states + DC + PR, 2000–2023 (1,248 raw `.txt` files)

**Reference:** [NBI Recording and Coding Guide (FHWA)](https://www.fhwa.dot.gov/bridge/mtguide.pdf)

## Schema

One row per `(bridge_id, year)`. Primary key: `(bridge_id, year)`.

### Identifiers & Location

| Column | Type | Description |
|--------|------|-------------|
| `bridge_id` | str | `{state_fips}_{county_fips}_{structure_number}` — primary key |
| `year` | int | Inspection year (2000–2023) |
| `state_code` | str | 2-digit FIPS state code (e.g. `"48"` = TX) |
| `county_code` | str | 3-digit FIPS county code |
| `county_fips` | str | `state_code + county_code` — used to join NOAA storm data |
| `structure_number` | str | FHWA structure number (whitespace-stripped) |
| `latitude` | float | Decimal degrees WGS-84 North |
| `longitude` | float | Decimal degrees WGS-84 West (negative) |

### Design & Material

| Column | NBI Item | Description |
|--------|----------|-------------|
| `year_built` | 027 | Year of original construction |
| `year_reconstructed` | 106 | Year of major reconstruction; `0` = never reconstructed |
| `main_span_material` | 043A | Main span material (`1`=Concrete, `3`=Steel, `5`=PSC, `7`=Wood) |
| `main_span_design` | 043B | Main span design type (`01`=Slab, `02`=Stringer, `05`=Box Beam) |
| `deck_structure_type` | 107 | Deck type (`1`=CIP Concrete, `2`=Precast, `3`=Open Grating) |
| `wearing_surface_type` | 108A | Wearing surface (`0`=Monolithic, `1`=Bituminous, `4`=Epoxy) |
| `membrane_type` | 108B | Waterproofing membrane (`0`=None, `1`=Built-up, `3`=Epoxy) |
| `deck_protection` | 108C | Rebar protection (`0`=None, `1`=Epoxy, `2`=Galvanized, `4`=Cathodic) |
| `design_load` | 031 | Design load standard (`5`=MS18+, `A`=HL-93) |
| `num_spans_main` | 045 | Number of spans in main unit |
| `max_span_length` | 048 | Maximum span length (metres) |
| `structure_length` | 049 | Total structure length (metres) |
| `deck_width` | 052 | Out-to-out deck width (metres) |
| `scour_critical` | 113 | Scour criticality (`3`=Critical, `8`=Not critical, `N`=Not over water) |

### Operational

| Column | NBI Item | Description |
|--------|----------|-------------|
| `adt` | 029 | Average Daily Traffic (vehicles/day) |
| `adtt_pct` | 109 | Truck percentage of ADT (%) |
| `operating_rating` | 064 | Operating load rating (metric tons) |
| `functional_class` | 026 | Route classification (`01`=Rural Interstate, `09`=Rural Local) |

### Condition Ratings (0–9 scale: 9=Excellent, 0=Failed)

| Column | NBI Item | Description |
|--------|----------|-------------|
| `deck_cond` | 058 | Deck condition rating — primary ML target source |
| `superstructure_cond` | 059 | Superstructure condition rating |
| `substructure_cond` | 060 | Substructure condition rating |
| `culvert_cond` | 062 | Culvert condition rating (`N` for non-culverts) |

### Derived Features & Target

| Column | Description |
|--------|-------------|
| `bridge_id` | Synthetic primary key: `{state_code}_{county_code}_{structure_number}` |
| `age` | `year − year_built`; negative values set to NaN |
| `deck_area` | `deck_width × structure_length` (m²) |
| `deck_cond_num` | `deck_cond` cast to integer; culverts (`N`) filtered out |
| `future_deck_cond_5yr` | Deck rating at `year + 5`; NaN if no future inspection |
| `deck_drop_5yr` | **ML target**: 1 if deck dropped ≥1 point in 5yr, 0 if stable, NaN if censored/repaired |

## ML Target (`deck_drop_5yr`)

Binary classification: did this bridge's deck condition rating drop by ≥ 1 point
within the next 5 years?

| Value | Meaning |
|-------|---------|
| `1` | Deck rating at `t+5` is at least 1 point lower → deteriorated |
| `0` | Deck rating at `t+5` is the same → stable |
| `NaN` | Censored (no future inspection) or repaired (rating went up) |

Positive rate: ~25% (5-year horizon). Rows from 2019–2023 are censored (no future data).

## Data Quality Notes

- Zero-encoded coordinates (`LAT=00000000`) are dropped.
- Longitude values outside `[-180, 0]` are dropped.
- Only NBI record type `1` (main records) is kept; continuation records are excluded.
- Culverts (`deck_cond = 'N'`) are excluded from the ML panel.
- Duplicate bridge records (same `bridge_id` + `year`) are deduplicated by keeping the first.

## Join Key

Join other bridgedeck datasets to NBI on:
- `(bridge_id, year)` for time-varying datasets (PRISM, NOAA)
- `bridge_id` for static datasets (NSHM, NFHL)
- `state_code` for state-level datasets (Salt)

## Related Datasets

| Repo | Description |
|------|-------------|
| `sweetapricity/bridgedeck-nbi` | **This dataset** — National Bridge Inventory, 2000–2023 |
| `sweetapricity/bridgedeck-prism` | PRISM climate features at bridge locations, 2000–2023 |
| `sweetapricity/bridgedeck-noaa` | NOAA storm event counts by county, 2000–2023 |
| `sweetapricity/bridgedeck-nshm` | USGS seismic hazard at bridge locations (static) |
| `sweetapricity/bridgedeck-nfhl` | FEMA flood zone classification at bridge locations (static) |
| `sweetapricity/bridgedeck-salt` | USGS road salt tiers by state (static) |

## Paper

> Ibrahim, A., Abdelkhalek, S., Zayed, T., Qureshi, A. H., & Mohammed Abdelkader, E.
> (2024). A comprehensive review of the key deterioration factors of concrete bridge
> decks. *Buildings*, 14(11), 3425.