County profile · official public datasets

Grant County, OK

476 public highway bridges tracked in the FHWA National Bridge Inventory: 28.2% rated Good, 64.5% Fair, 7.4% Poor.

476
Public bridges: 28.2%
Good condition: 7.4%
Poor condition

The verdict

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

Grant County pairs a higher-than-median Poor-condition share among rated counties in the state with a newer average build year than the state inventory.

47th
of 77 on Poor share: 7.4%
Poor-condition share: 476
public highway bridges: 1988
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.

Grant County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Grant County ranks #47 of 77 Oklahoma counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 7.4%). Grant County, Oklahoma contains 476 public highway bridges. Roughly 28.2% are rated “Good,” 64.5% “Fair,” and 7.4% “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

476

Public highway bridges in Grant County

Good condition

28.2%

134 of 476 rated 7-9

Fair condition

64.5%

307 of 476 rated 5-6

Poor condition

7.4%

35 of 476 rated 4 or below

In-state Poor-share rank

#47 of 77

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

Condition distribution

Share of 476 NBI-tracked bridges by lowest applicable component rating.

Good

28.2% (134)

Fair

64.5% (307)

Poor

7.4% (35)

Grant County's Poor-condition bridges carry 1,731 vehicle crossings a day

That is 1.6% of the county's reported daily bridge traffic on 7.4% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 49 crossings a day against 394 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 476 of 476 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

29% of Grant County's bridges have passed the 50-year mark

138 of the 476 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 28.2% 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 26% of the county's Poor-condition bridge traffic

N2920 over CREEK, built 1995, carries 450 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 35-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 1,731 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1920s

7
1930s

34
1940s

35
1950s

37
1960s

23
1970s

4
1980s

41
1990s

82
2000s

59
2010s

118
2020s

36

What this shows Construction peaked in the 2010s, when 118 of the county's bridges still in the inventory were built, which is 24.8% of those with a recorded year. That cohort is now 5 to 14 years old in the 2024 inventory. Its average build year is 1988, 11 years newer than the Oklahoma average of 1977.

How Grant County compares with Oklahoma's closest counties by inventory size

The 5 Oklahoma counties nearest Grant County in number of bridges, with their condition splits. Its 7.4% Poor share is the 4th-lowest of these 6. Its average build year of 1988 against a peer-group mean of 1976 is 12 years newer.

Showing the 5 closest of 76 Oklahoma counties eligible for comparison.

Bridge inventory size and condition shares for Grant County and the 5 Oklahoma counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Canadian County	493	49.5%	47.1%	3.4%	1986
Kiowa County	477	65.4%	31.7%	2.9%	1973
Grant County (this page)	476	28.2%	64.5%	7.4%	1988
Le Flore County	469	44.3%	44.3%	11.3%	1967
Lincoln County	450	37.1%	49.6%	13.3%	1974
Grady County	449	25.6%	67.3%	7.1%	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 Grant 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 Grant County, both outside Oklahoma so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside OK (476 bridges here).

Johnson County, MO · 476 bridges
Providence County, RI · 476 bridges
Tangipahoa County, LA · 477 bridges
Horry County, SC · 479 bridges

Similar average build year

Nearest mean year-built outside OK (1988 here).

Travis County, TX · avg 1988 · 1,544 bridges
Loudoun County, VA · avg 1988 · 442 bridges
Licking County, OH · avg 1988 · 439 bridges
Vernon County, MO · avg 1988 · 401 bridges

Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.

All 476 Good 134 Fair 307 Poor 35

Good-condition bridges (134)

Sort:

Grant County Bridge Snapshot

Condition distribution

Grant County's Poor-condition bridges carry 1,731 vehicle crossings a day

29% of Grant County's bridges have passed the 50-year mark

One structure carries 26% of the county's Poor-condition bridge traffic

How Grant County compares with Oklahoma'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 (134)

E0020

N2960

E0090

E0060

N2960

E0010

E0200

E0200

E0080

E0090

N3010

E0160

E0160

E0200

N2830

E0260

N3020

N3010

N3000

N2760

E0190

E0100

E0120

E0200

E0200

N2980

E0210

N3010 CREEK

S.H. 11

S.H. 11

N3100

S.H. 11

U.S. 81

N2780

U.S. 64

U.S. 64

U.S. 64

E0200

E0020

E0130

N2800

U.S. 81

S.H. 11

U.S. 81

E0090

E0180

U.S. 60

S.H. 11

S.H. 11

N2960

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