County profile · official public datasets

Seminole County, OK

298 public highway bridges tracked in the FHWA National Bridge Inventory: 38.6% rated Good, 49.7% Fair, 11.7% Poor.

298
Public bridges: 38.6%
Good condition: 11.7%
Poor condition

The verdict

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

Seminole 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.

64th
of 77 on Poor share: 11.7%
Poor-condition share: 298
public highway bridges: 1966
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.

Seminole County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Seminole County ranks #64 of 77 Oklahoma counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 11.7%). Seminole County, Oklahoma contains 298 public highway bridges. Roughly 38.6% are rated “Good,” 49.7% “Fair,” and 11.7% “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.

Total bridges

298

Public highway bridges in Seminole County

Good condition

38.6%

115 of 298 rated 7-9

Fair condition

49.7%

148 of 298 rated 5-6

Poor condition

11.7%

35 of 298 rated 4 or below

In-state Poor-share rank

#64 of 77

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

Condition distribution

Share of 298 NBI-tracked bridges by lowest applicable component rating.

Good

38.6% (115)

Fair

49.7% (148)

Poor

11.7% (35)

Seminole County's Poor-condition bridges carry 26,155 vehicle crossings a day

That is 5.4% of the county's reported daily bridge traffic on 11.7% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 747 crossings a day against 2,188 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 298 of 298 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

61.4% of Seminole County's bridges have passed the 50-year mark

183 of the 298 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 38.6% 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 28.3% of the county's Poor-condition bridge traffic

U.S. 270 over CREEK, built 1943, carries 7,400 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 26,155 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1910s

6
1920s

15
1930s

58
1940s

39
1950s

21
1960s

38
1970s

15
1980s

19
1990s

28
2000s

28
2010s

21
2020s

10

What this shows Construction peaked in the 1930s, when 58 of the county's bridges still in the inventory were built, which is 19.5% of those with a recorded year. That cohort is now 85 to 94 years old in the 2024 inventory. Its average build year is 1966, 11 years older than the Oklahoma average of 1977.

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

The 5 Oklahoma counties nearest Seminole County in number of bridges, with their condition splits. Its 11.7% Poor share is the 5th-lowest of these 6. Its average build year of 1966 against a peer-group mean of 1976 is 10 years older.

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

Bridge inventory size and condition shares for Seminole County and the 5 Oklahoma counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Okmulgee County	310	33.2%	49.4%	17.4%	1971
Woods County	310	24.5%	71.6%	3.9%	1986
Seminole County (this page)	298	38.6%	49.7%	11.7%	1966
Kingfisher County	297	23.9%	69.4%	6.7%	1987
Jackson County	292	58.6%	39%	2.4%	1964
Bryan County	286	41.6%	48.6%	9.8%	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 Seminole 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 Seminole County, both outside Oklahoma so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside OK (298 bridges here).

Sarasota County, FL · 298 bridges
Rutherford County, NC · 298 bridges
Richland County, WI · 298 bridges
St. Croix County, WI · 298 bridges

Similar average build year

Nearest mean year-built outside OK (1966 here).

Butler County, KS · avg 1966 · 591 bridges
Grafton County, NH · avg 1966 · 544 bridges
Queens County, NY · avg 1966 · 514 bridges
Lehigh County, PA · avg 1966 · 381 bridges

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

All 298 Good 115 Fair 148 Poor 35

All bridges (298)

Sort:

Seminole County Bridge Snapshot

Condition distribution

Seminole County's Poor-condition bridges carry 26,155 vehicle crossings a day

61.4% of Seminole County's bridges have passed the 50-year mark

One structure carries 28.3% of the county's Poor-condition bridge traffic

How Seminole 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

All bridges (298)

6770C

E1120

E1390

E1410

N3630

E1270

N3590

6770C

N3500

6769C

6769C

6769C

6750C

6776C

6718C

N3580

E1230

S.H. 9

S.H. 9

6764C

E1140

6710C

D1272

D3665

E1440

I-40

I-40

I-40

I-40

U.S. 270

S.H. 56

6704C

S.H. 56

6730C

6710C

S.H. 3E

N3530

E1130

S.H. 9

E1380

E1380

6732C

E1375

N3520

S.H. 3E

NS3650

S.H. 99A

S.H. 99A

S.H. 99A

S.H. 59

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