County profile · official public datasets

Marshall County, OK

78 public highway bridges tracked in the FHWA National Bridge Inventory: 51.3% rated Good, 37.2% Fair, 11.5% Poor.

78
Public bridges: 51.3%
Good condition: 11.5%
Poor condition

The verdict

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

Marshall 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.

61st
of 77 on Poor share: 11.5%
Poor-condition share: 78
public highway bridges: 1968
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.

Marshall County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Marshall County ranks #61 of 77 Oklahoma counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 11.5%). Marshall County, Oklahoma contains 78 public highway bridges. Roughly 51.3% are rated “Good,” 37.2% “Fair,” and 11.5% “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

Public highway bridges in Marshall County

Good condition

51.3%

40 of 78 rated 7-9

Fair condition

37.2%

29 of 78 rated 5-6

Poor condition

11.5%

9 of 78 rated 4 or below

In-state Poor-share rank

#61 of 77

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

Condition distribution

Share of 78 NBI-tracked bridges by lowest applicable component rating.

Good

51.3% (40)

Fair

37.2% (29)

Poor

11.5% (9)

Marshall County's Poor-condition bridges carry 800 vehicle crossings a day

That is 0.8% of the county's reported daily bridge traffic on 11.5% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 89 crossings a day against 738 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 78 of 78 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

55.1% of Marshall County's bridges have passed the 50-year mark

43 of the 78 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 51.3% 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 12.5% of the county's Poor-condition bridge traffic

N3580 MOORE RD over ROCK CREEK, built 1936, carries 100 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 9-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 800 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1930s

20
1940s

12
1950s

3
1960s

7
1970s

1
1980s

13
1990s

8
2000s

5
2010s

6
2020s

3

What this shows Construction peaked in the 1930s, when 20 of the county's bridges still in the inventory were built, which is 25.6% of those with a recorded year. That cohort is now 85 to 94 years old in the 2024 inventory. Its average build year is 1968, 9 years older than the Oklahoma average of 1977.

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

The 5 Oklahoma counties nearest Marshall County in number of bridges, with their condition splits. Its 11.5% Poor share is the 5th-lowest of these 6. Its average build year of 1968 against a peer-group mean of 1974 is 6 years older.

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

Bridge inventory size and condition shares for Marshall County and the 5 Oklahoma counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Harper County	128	33.6%	64.8%	1.6%	1975
Nowata County	126	44.4%	42.9%	12.7%	1980
Texas County	111	40.5%	58.6%	0.9%	1974
Harmon County	106	75.5%	23.6%	0.9%	1968
Cimarron County	93	49.5%	49.5%	1.1%	1972
Marshall County (this page)	78	51.3%	37.2%	11.5%	1968

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

Similar inventory size

Nearest county inventories outside OK (78 bridges here).

Winston County, AL · 78 bridges
Marion County, FL · 78 bridges
Bryan County, GA · 78 bridges
Macon County, GA · 78 bridges

Similar average build year

Nearest mean year-built outside OK (1968 here).

Montgomery County, PA · avg 1968 · 828 bridges
San Joaquin County, CA · avg 1968 · 644 bridges
Providence County, RI · avg 1968 · 476 bridges
Imperial County, CA · avg 1968 · 444 bridges

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

All 78 Good 40 Fair 29 Poor 9

Good-condition bridges (40)

Sort:

Marshall County Bridge Snapshot

Condition distribution

Marshall County's Poor-condition bridges carry 800 vehicle crossings a day

55.1% of Marshall County's bridges have passed the 50-year mark

One structure carries 12.5% of the county's Poor-condition bridge traffic

How Marshall 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 (40)

S.H. 199

E2000

E2030 SPARLIN RD.

4802C JAGGER RD

4810C

D3540

D3540

4804C LINN RD.

4810C

4804C

4832C ENOS RD

E2010

4804C

IRR N3395

E2050 ARCHARD RD

IRR 4820C

4808C PARISH RD.

E2050

E1975

N3490 (S. 5TH AVE)

E2030 W. SMILEY RD

E2030

N3520

S.H. 199

U.S. 70

N3450 (LEE ROAD)

4810C

4808C

N3528

S.H. 99

4822C

S.H. 99

E2070

S.H. 32

4812C

U.S. 70

4824C SIMPSON RD

4828C

N3423

S.H. 99 / U.S. 377

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