Total bridges
104
Public highway bridges in Decatur County
County profile · official public datasets
Decatur County, TN
104 public highway bridges tracked in the FHWA National Bridge Inventory: 35.6% rated Good, 63.5% Fair, 1% Poor.
- 104
- Public bridges
- 35.6%
- Good condition
- 1%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Decatur County pairs a top-10% lowest Poor-condition share among rated counties in the state with a newer average build year than the state inventory.
- Top 6%
- lowest Poor share in state
- 1%
- Poor-condition share
- 104
- public highway bridges
- 1982
- 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.
Decatur County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Decatur County ranks #6 of 95 Tennessee counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 1%). Decatur County, Tennessee contains 104 public highway bridges. Roughly 35.6% are rated “Good,” 63.5% “Fair,” and 1% “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
35.6%
37 of 104 rated 7-9
Fair condition
63.5%
66 of 104 rated 5-6
Poor condition
1%
1 of 104 rated 4 or below
In-state Poor-share rank
#6 of 95
Among Tennessee counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 104 NBI-tracked bridges by lowest applicable component rating.
Good 35.6% (37)
Fair 63.5% (66)
Poor 1% (1)
Decatur County's Poor-condition bridges carry 294 vehicle crossings a day
That is 0.2% of the county's reported daily bridge traffic on 1% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 294 crossings a day against 1,156 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 104 of 104 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
28.8% of Decatur County's bridges have passed the 50-year mark
30 of the 104 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 35.6% 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 100% of the county's Poor-condition bridge traffic
FAS 69 over STEWMANS CREEK, built 1950, carries 294 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 1-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 294 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Decatur County's bridges were built
104 bridges with a recorded construction year, grouped by decade
- 1930s 7
1930–1939
7 bridges
- 1940s 2
1940–1949
2 bridges
- 1950s
1950–1959
12 bridges
- 1960s 5
1960–1969
5 bridges
- 1970s
1970–1979
14 bridges
- 1980s
1980–1989
22 bridges
- 1990s
1990–1999
19 bridges
- 2000s
2000–2009
12 bridges
- 2010s
2010–2019
9 bridges
- 2020s 2
2020–2029
2 bridges
What this shows Construction peaked in the 1980s, when 22 of the county's bridges still in the inventory were built, which is 21.2% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year is 1982, 5 years newer than the Tennessee average of 1977.
How Decatur County compares with Tennessee's closest counties by inventory size
The 5 Tennessee counties nearest Decatur County in number of bridges, with their condition splits. Its 1% Poor share is the 1st-lowest of these 6. Its average build year of 1982 against a peer-group mean of 1977 is 5 years newer.
Showing the 5 closest of 94 Tennessee counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Scott County | 111 | 24.3% | 71.2% | 4.5% | 1973 |
| Johnson County | 109 | 44% | 51.4% | 4.6% | 1972 |
| Decatur County (this page) | 104 | 35.6% | 63.5% | 1% | 1982 |
| DeKalb County | 100 | 23% | 70% | 7% | 1977 |
| Rhea County | 100 | 34% | 59% | 7% | 1979 |
| Claiborne County | 98 | 35.7% | 60.2% | 4.1% | 1985 |
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 Decatur 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 Decatur County, both outside Tennessee so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside TN (104 bridges here).
- Nassau County, FL · 104 bridges
- Brooks County, GA · 104 bridges
- Grady County, GA · 104 bridges
- Bonner County, ID · 104 bridges
Similar average build year
Nearest mean year-built outside TN (1982 here).
- Oklahoma County, OK · avg 1982 · 1,216 bridges
- Jackson County, MO · avg 1982 · 930 bridges
- Milwaukee County, WI · avg 1982 · 893 bridges
- Champaign County, IL · avg 1982 · 727 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Poor-condition bridges (1)
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.