County profile · official public datasets

Carbon County, WY

206 public highway bridges tracked in the FHWA National Bridge Inventory: 38.8% rated Good, 54.4% Fair, 6.8% Poor.

206
Public bridges: 38.8%
Good condition: 6.8%
Poor condition

The verdict

According to the Federal Highway Administration's 2024 National Bridge Inventory.

Carbon County posts a higher-than-median Poor-condition share among rated counties in the state across mid-size county bridge inventory.

13th
of 23 on Poor share: 6.8%
Poor-condition share: 206
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.

Carbon County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Carbon County ranks #13 of 23 Wyoming counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 6.8%). Carbon County, Wyoming contains 206 public highway bridges. Roughly 38.8% are rated “Good,” 54.4% “Fair,” and 6.8% “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.

Total bridges

206

Public highway bridges in Carbon County

Good condition

38.8%

80 of 206 rated 7-9

Fair condition

54.4%

112 of 206 rated 5-6

Poor condition

6.8%

14 of 206 rated 4 or below

In-state Poor-share rank

#13 of 23

Among Wyoming counties with 5+ bridges, lower share ranks better

Condition distribution

Share of 206 NBI-tracked bridges by lowest applicable component rating.

Good

38.8% (80)

Fair

54.4% (112)

Poor

6.8% (14)

Carbon County's Poor-condition bridges carry 3,110 vehicle crossings a day

That is 0.6% of the county's reported daily bridge traffic on 6.8% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 222 crossings a day against 1,703 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 206 of 206 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

60.7% of Carbon County's bridges have passed the 50-year mark

125 of the 206 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 38.8% 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 63.8% of the county's Poor-condition bridge traffic

S 6th Street over UPRR, built 1966, carries 1,984 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 3,110 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1910s

3
1920s

1
1930s

3
1940s

6
1950s

32
1960s

63
1970s

29
1980s

28
1990s

11
2000s

16
2010s

13
2020s

1

What this shows Construction peaked in the 1960s, when 63 of the county's bridges still in the inventory were built, which is 30.6% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year (1973) matches the Wyoming average (1976).

How Carbon County compares with Wyoming's closest counties by inventory size

The 5 Wyoming counties nearest Carbon County in number of bridges, with their condition splits. Its 6.8% Poor share is the 5th-lowest of these 6. Its average build year of 1973 against a peer-group mean of 1976 is in line with the group.

Showing the 5 closest of 22 Wyoming counties eligible for comparison.

Bridge inventory size and condition shares for Carbon County and the 5 Wyoming counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Carbon County (this page)	206	38.8%	54.4%	6.8%	1973
Johnson County	204	26.5%	70.6%	2.9%	1970
Sweetwater County	191	28.8%	62.8%	8.4%	1976
Park County	187	37.4%	58.3%	4.3%	1979
Fremont County	177	47.5%	46.3%	6.2%	1981
Crook County	176	30.7%	67.6%	1.7%	1974

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 Wyoming so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside WY (206 bridges here).

Dale County, AL · 206 bridges
Henry County, IN · 206 bridges
Audubon County, IA · 206 bridges
Bourbon County, KS · 206 bridges

Similar average build year

Nearest mean year-built outside WY (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.

All 206 Good 80 Fair 112 Poor 14

Good-condition bridges (80)

Sort:

Carbon County Bridge Snapshot

Condition distribution

Carbon County's Poor-condition bridges carry 3,110 vehicle crossings a day

60.7% of Carbon County's bridges have passed the 50-year mark

One structure carries 63.8% of the county's Poor-condition bridge traffic

How Carbon County compares with Wyoming's closest counties by inventory size

Nationwide counties with similar inventory size or average build year

Similar inventory size

Similar average build year

Good-condition bridges (80)

Forest Road 443

NFSR 500

NFSR 101

NFSR 100

NFSR 452

2317: THREE FORKS-

NFSR 443

3306: MUDDY CREEK

NFSR 219

NFSR 241

WYO 130

WYO 76

Cb Cnty Rd 752

NFSR 851

NFSR 200

Cb Cnty Rd 400

NFSR 100

I-80 EBL

WYO 70

WYO 130

NFSR 236

I-80 EBL

I-80 EBL

NFSR 496

Cb Cnty Rd 121

NFSR 105

I-80 WBL

I-80 EBL

I-80 WBL

US 30

WYO 230

WYO 70

WYO 72

Cb Cnty Rd 320

WYO 487

WYO 230

WYO 789

WYO 789

WYO 70

WYO 130

WYO 72

I-80 EBL

WYO 789

Cb Cnty Rd 401

Cb Cnty Rd 401

WYO 789

WYO 130

US 30

I-80 WBL

US 287

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