Total bridges
233
Public highway bridges in Washington County
County profile · official public datasets
Washington County, IL
233 public highway bridges tracked in the FHWA National Bridge Inventory: 50.6% rated Good, 43.3% Fair, 6% Poor.
- 233
- Public bridges
- 50.6%
- Good condition
- 6%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Washington County pairs a top-quartile lowest Poor-condition share among rated counties in the state with an older average build year than the state inventory.
- Top 25%
- lowest Poor share in state
- 6%
- Poor-condition share
- 233
- public highway bridges
- 1973
- avg year built
Poor is an FHWA condition category from the lowest applicable component rating (4 or below), not a live crossing-safety or closure decision. Rankings cover counties with at least five public highway bridges.
Washington County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Washington County ranks #25 of 102 Illinois counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 6%). Washington County, Illinois contains 233 public highway bridges. Roughly 50.6% are rated “Good,” 43.3% “Fair,” and 6% “Poor.” Poor means the lowest applicable deck, superstructure, substructure, or culvert rating is 4 or below on the 0–9 NBI scale. It is a condition category, not a live safety or closure decision.
Responsible agencies inspect covered bridges on risk-based intervals under current NBIS rules and submit inventory data to FHWA annually. The list below shows every NBI-tracked bridge in the county. Use the “Sort by” controls to change the ordering, and click any row for its reported inspection date, traffic count, and condition fields.
Source: FHWA National Bridge Inventory. See methodology for full definitions.
Good condition
50.6%
118 of 233 rated 7-9
Fair condition
43.3%
101 of 233 rated 5-6
Poor condition
6%
14 of 233 rated 4 or below
In-state Poor-share rank
#25 of 102
Among Illinois counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 233 NBI-tracked bridges by lowest applicable component rating.
Good 50.6% (118)
Fair 43.3% (101)
Poor 6% (14)
Washington County's Poor-condition bridges carry 41,370 vehicle crossings a day
That is 8.8% of the county's reported daily bridge traffic on 6% of its bridges: Poor-condition structures carry more traffic than their share of the inventory. Each Poor bridge averages 2,955 crossings a day against 1,003 for a Good-condition one. A Poor rating is a condition category, not a closure or a live safety judgement; it means the lowest applicable component rating is 4 or below.
Computed over the 233 of 233 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
42.9% of Washington County's bridges have passed the 50-year mark
100 of the 233 bridges with a recorded construction year were built in 1974 or earlier. Age alone is not a defect: a well-maintained older bridge can rate Good, and 50.6% of this county's inventory does. Even so, this older cohort is the population from which future Poor ratings are drawn, which is why the age profile below matters alongside the condition split above.
Cutoff derives from the 2024 release year minus a 50-year design life. Source: FHWA National Bridge Inventory, 2024 release.
One structure carries 33.8% of the county's Poor-condition bridge traffic
I-64 EB over Prairie Rd Abandoned UPR, built 1972, carries 14,000 vehicles a day, the most of any Poor-rated structure here. The county's Poor-condition exposure is concentrated rather than evenly spread, so the 14-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 41,370 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Washington County's bridges were built
233 bridges with a recorded construction year, grouped by decade
- 1900s 1
1900–1909
1 bridges
- 1910s 11
1910–1919
11 bridges
- 1920s 18
1920–1929
18 bridges
- 1930s 17
1930–1939
17 bridges
- 1940s 2
1940–1949
2 bridges
- 1950s 4
1950–1959
4 bridges
- 1960s
1960–1969
26 bridges
- 1970s
1970–1979
27 bridges
- 1980s
1980–1989
50 bridges
- 1990s
1990–1999
48 bridges
- 2000s 17
2000–2009
17 bridges
- 2010s 8
2010–2019
8 bridges
- 2020s 4
2020–2029
4 bridges
What this shows Construction peaked in the 1980s, when 50 of the county's bridges still in the inventory were built, which is 21.5% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year is 1973, 6 years older than the Illinois average of 1979.
How Washington County compares with Illinois's closest counties by inventory size
The 5 Illinois counties nearest Washington County in number of bridges, with their condition splits. Its 6% Poor share is the 3rd-lowest of these 6. Its average build year of 1973 against a peer-group mean of 1983 is 10 years older.
Showing the 5 closest of 101 Illinois counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Morgan County | 234 | 48.7% | 42.7% | 8.5% | 1984 |
| Washington County (this page) | 233 | 50.6% | 43.3% | 6% | 1973 |
| Douglas County | 232 | 76.3% | 22.4% | 1.3% | 1982 |
| Clark County | 230 | 62.6% | 32.6% | 4.8% | 1978 |
| Jackson County | 228 | 66.2% | 27.2% | 6.6% | 1987 |
| McHenry County | 227 | 41.4% | 38.3% | 20.3% | 1983 |
Each share is of that county's own total tracked bridges; peers are the counties with 5 or more bridges whose inventory size is closest to Washington County's. Source: FHWA National Bridge Inventory, 2024 release.
Nationwide counties with similar inventory size or average build year
Two NBI-derived peer sets for Washington County, both outside Illinois so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside IL (233 bridges here).
- Pickens County, AL · 233 bridges
- Lawrence County, MO · 233 bridges
- Oswego County, NY · 233 bridges
- Mayes County, OK · 233 bridges
Similar average build year
Nearest mean year-built outside IL (1973 here).
- Jefferson County, AL · avg 1973 · 1,068 bridges
- Erie County, NY · avg 1973 · 906 bridges
- Davidson County, TN · avg 1973 · 832 bridges
- Lancaster County, PA · avg 1973 · 801 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Fair-condition bridges (101)
Read our methodology - how this data is sourced, computed, and verified.
Related
Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainBridges
Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.