Total bridges
73
Public highway bridges in Carbon County
County profile · official public datasets
Carbon County, UT
73 public highway bridges tracked in the FHWA National Bridge Inventory: 19.2% rated Good, 78.1% Fair, 2.7% Poor.
- 73
- Public bridges
- 19.2%
- Good condition
- 2.7%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Carbon County pairs a higher-than-median Poor-condition share among rated counties in the state with an older average build year than the state inventory.
- 15th
- of 29 on Poor share
- 2.7%
- Poor-condition share
- 73
- public highway bridges
- 1974
- 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.
Carbon County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Carbon County ranks #15 of 29 Utah counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 2.7%). Carbon County, Utah contains 73 public highway bridges. Roughly 19.2% are rated “Good,” 78.1% “Fair,” and 2.7% “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
19.2%
14 of 73 rated 7-9
Fair condition
78.1%
57 of 73 rated 5-6
Poor condition
2.7%
2 of 73 rated 4 or below
In-state Poor-share rank
#15 of 29
Among Utah counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 73 NBI-tracked bridges by lowest applicable component rating.
Good 19.2% (14)
Fair 78.1% (57)
Poor 2.7% (2)
Carbon County's Poor-condition bridges carry 94 vehicle crossings a day
That is 0% of the county's reported daily bridge traffic on 2.7% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 47 crossings a day against 2,731 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 73 of 73 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
35.6% of Carbon County's bridges have passed the 50-year mark
26 of the 73 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 19.2% 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 79.8% of the county's Poor-condition bridge traffic
6558: COTTONWOOD C over NINE MILE CREEK, built 1994, carries 75 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 2-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 94 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Carbon County's bridges were built
73 bridges with a recorded construction year, grouped by decade
- 1900s 1
1900–1909
1 bridges
- 1910s 2
1910–1919
2 bridges
- 1920s 1
1920–1929
1 bridges
- 1930s 5
1930–1939
5 bridges
- 1940s 1
1940–1949
1 bridges
- 1950s
1950–1959
10 bridges
- 1960s 5
1960–1969
5 bridges
- 1970s
1970–1979
13 bridges
- 1980s
1980–1989
15 bridges
- 1990s
1990–1999
10 bridges
- 2000s
2000–2009
8 bridges
- 2010s 1
2010–2019
1 bridges
- 2020s 1
2020–2029
1 bridges
What this shows Construction peaked in the 1980s, when 15 of the county's bridges still in the inventory were built, which is 20.5% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year is 1974, 10 years older than the Utah average of 1984.
How Carbon County compares with Utah's closest counties by inventory size
The 5 Utah counties nearest Carbon County in number of bridges, with their condition splits. Its 2.7% Poor share is the 3rd-lowest of these 6. Its average build year of 1974 against a peer-group mean of 1982 is 8 years older.
Showing the 5 closest of 28 Utah counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Uintah County | 91 | 31.9% | 64.8% | 3.3% | 1989 |
| Duchesne County | 84 | 26.2% | 67.9% | 6% | 1984 |
| Carbon County (this page) | 73 | 19.2% | 78.1% | 2.7% | 1974 |
| Millard County | 72 | 12.5% | 86.1% | 1.4% | 1978 |
| Iron County | 70 | 10% | 88.6% | 1.4% | 1977 |
| Juab County | 60 | 8.3% | 88.3% | 3.3% | 1980 |
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 Carbon 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 Carbon County, both outside Utah so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside UT (73 bridges here).
- Stone County, AR · 73 bridges
- Levy County, FL · 73 bridges
- Putnam County, FL · 73 bridges
- Dade County, GA · 73 bridges
Similar average build year
Nearest mean year-built outside UT (1974 here).
- Knox County, TN · avg 1974 · 588 bridges
- Summit County, OH · avg 1974 · 563 bridges
- Onondaga County, NY · avg 1974 · 472 bridges
- Orange County, NY · avg 1974 · 472 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Fair-condition bridges (57)
COUNTY ROAD
FairOver: PRICE RIVER
0.5 MILE S. OF WELLINGTON, Carbon, UT
Built 1976 Load: 76.1 t ADT: 123
US-6 (SR-6)
FairOver: SPRING CANYON WASH
Just North of Helper int., Carbon, UT
Built 2005 Load: 79.4 t ADT: 354
US-6 (SR-6)
FairOver: PRICE RIVER
3 MI.NORTHWEST OF PRICE, Carbon, UT
Built 1952 Load: 85.5 t ADT: 15,754
650 NORTH STREET
FairOver: MEADS WASH
650 NO.CEDAR HILLS DRIVE, Carbon, UT
Built 1982 Load: 96.6 t ADT: 315
RIDGE ROAD -CO.RD.
FairOver: COAL CREEK
EAST OF WELLINGTON, Carbon, UT
Built 1990 Load: 96.6 t ADT: 7,897
US-6 (SR-6)
FairOver: CARBON CANAL
1.3 MILE SO. OF BLUE CUT, Carbon, UT
Built 1978 Load: 96.6 t ADT: 14,042
US-6 (SR-6)
FairOver: GORDON CREEK
5 MILE NW OF PRICE, Carbon, UT
Built 1978 Load: 99.9 t ADT: 14,042
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.