County profile · official public datasets

Grady County, OK

449 public highway bridges tracked in the FHWA National Bridge Inventory: 25.6% rated Good, 67.3% Fair, 7.1% Poor.

449
Public bridges: 25.6%
Good condition: 7.1%
Poor condition

The verdict

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

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

45th
of 77 on Poor share: 7.1%
Poor-condition share: 449
public highway bridges: 1980
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.

Grady County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Grady County ranks #45 of 77 Oklahoma counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 7.1%). Grady County, Oklahoma contains 449 public highway bridges. Roughly 25.6% are rated “Good,” 67.3% “Fair,” and 7.1% “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.

Total bridges

449

Public highway bridges in Grady County

Good condition

25.6%

115 of 449 rated 7-9

Fair condition

67.3%

302 of 449 rated 5-6

Poor condition

7.1%

32 of 449 rated 4 or below

In-state Poor-share rank

#45 of 77

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

Condition distribution

Share of 449 NBI-tracked bridges by lowest applicable component rating.

Good

25.6% (115)

Fair

67.3% (302)

Poor

7.1% (32)

Grady County's Poor-condition bridges carry 9,048 vehicle crossings a day

That is 1.1% of the county's reported daily bridge traffic on 7.1% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 283 crossings a day against 4,211 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 449 of 449 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

35.4% of Grady County's bridges have passed the 50-year mark

159 of the 449 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 25.6% 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 26.1% of the county's Poor-condition bridge traffic

N2830 (16 ST) over LINE CREEK, built 1933, carries 2,358 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 32-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 9,048 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1910s

2
1920s

14
1930s

26
1940s

27
1950s

17
1960s

59
1970s

19
1980s

82
1990s

124
2000s

47
2010s

23
2020s

9

What this shows Construction peaked in the 1990s, when 124 of the county's bridges still in the inventory were built, which is 27.6% of those with a recorded year. That cohort is now 25 to 34 years old in the 2024 inventory. Its average build year (1980) matches the Oklahoma average (1977).

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

The 5 Oklahoma counties nearest Grady County in number of bridges, with their condition splits. Its 7.1% Poor share is the 2nd-lowest of these 6. Its average build year of 1980 against a peer-group mean of 1976 is in line with the group.

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

Bridge inventory size and condition shares for Grady County and the 5 Oklahoma counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Kiowa County	477	65.4%	31.7%	2.9%	1973
Grant County	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 (this page)	449	25.6%	67.3%	7.1%	1980
Caddo County	424	24.1%	63.4%	12.5%	1979

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 Grady 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 Grady County, both outside Oklahoma so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside OK (449 bridges here).

Washington County, AR · 449 bridges
Sioux County, IA · 449 bridges
Barton County, KS · 449 bridges
Dauphin County, PA · 449 bridges

Similar average build year

Nearest mean year-built outside OK (1980 here).

Miami-Dade County, FL · avg 1980 · 1,057 bridges
Pulaski County, AR · avg 1980 · 721 bridges
McLennan County, TX · avg 1980 · 714 bridges
Hinds County, MS · avg 1980 · 663 bridges

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

All 449 Good 115 Fair 302 Poor 32

Fair-condition bridges (302)

Sort:

Grady County Bridge Snapshot

Condition distribution

Grady County's Poor-condition bridges carry 9,048 vehicle crossings a day

35.4% of Grady County's bridges have passed the 50-year mark

One structure carries 26.1% of the county's Poor-condition bridge traffic

How Grady 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

Fair-condition bridges (302)

N2825 (21 ST)

E1358 (IOWA AVE)

N2841 SECOND ST.

N2839 (3RD ST.)

E1365 ARKANSAS ST.

U.S. 277

E1365 (GEORGIA)

N2935

E1444

E1450

FAS 0831C

S.H. 19

2664C

N2770

E TYLER DR

2614C

N2890

N2790

2617C

2654C

N2820

E1250

N2835 (9 ST)

E TYLER DR

CO. RD. N2940

2684C

N2790

S.H. 4

E1420

E1490

N2750

E1260

CO. RD. N2860

CO. RD. E1270

CO. RD. N2990

CO. RD. 2686C

CO. RD. 2648C

S.H. 19

U.S. 277

CO. RD. E1345

2674C

E1340

2686C

2606C

2602C

E1260

CO. RD. E1410

CO. RD. N2880

N RICHLAND RD

CO. RD. FAS 2603

Related