County profile · official public datasets

Adair County, MO

301 public highway bridges tracked in the FHWA National Bridge Inventory: 60.8% rated Good, 32.6% Fair, 6.6% Poor.

301
Public bridges: 60.8%
Good condition: 6.6%
Poor condition

The verdict

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

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

Top 32%
lowest Poor share in state: 6.6%
Poor-condition share: 301
public highway bridges: 1992
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.

Adair County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Adair County ranks #37 of 115 Missouri counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 6.6%). Adair County, Missouri contains 301 public highway bridges. Roughly 60.8% are rated “Good,” 32.6% “Fair,” and 6.6% “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

301

Public highway bridges in Adair County

Good condition

60.8%

183 of 301 rated 7-9

Fair condition

32.6%

98 of 301 rated 5-6

Poor condition

6.6%

20 of 301 rated 4 or below

In-state Poor-share rank

#37 of 115

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

Condition distribution

Share of 301 NBI-tracked bridges by lowest applicable component rating.

Good

60.8% (183)

Fair

32.6% (98)

Poor

6.6% (20)

Adair County's Poor-condition bridges carry 4,563 vehicle crossings a day

That is 3% of the county's reported daily bridge traffic on 6.6% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 228 crossings a day against 239 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 301 of 301 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

14% of Adair County's bridges have passed the 50-year mark

42 of the 301 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 60.8% 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 57.7% of the county's Poor-condition bridge traffic

MO 6 E over HOGE BR, built 1926, carries 2,634 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 20-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 4,563 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

1
1910s

1
1920s

5
1930s

10
1940s

7
1950s

12
1960s

3
1970s

10
1980s

34
1990s

91
2000s

73
2010s

41
2020s

13

What this shows Construction peaked in the 1990s, when 91 of the county's bridges still in the inventory were built, which is 30.2% of those with a recorded year. That cohort is now 25 to 34 years old in the 2024 inventory. Its average build year is 1992, 13 years newer than the Missouri average of 1979.

How Adair County compares with Missouri's closest counties by inventory size

The 5 Missouri counties nearest Adair County in number of bridges, with their condition splits. Its 6.6% Poor share is the 3rd-lowest of these 6. Its average build year of 1992 against a peer-group mean of 1982 is 10 years newer.

Showing the 5 closest of 114 Missouri counties eligible for comparison.

Bridge inventory size and condition shares for Adair County and the 5 Missouri counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Audrain County	314	41.4%	53.8%	4.8%	1987
Linn County	313	39%	43.5%	17.6%	1980
Callaway County	303	39.3%	54.5%	6.3%	1978
Adair County (this page)	301	60.8%	32.6%	6.6%	1992
Newton County	300	39%	54.3%	6.7%	1978
Macon County	291	42.6%	49.8%	7.6%	1986

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

Similar inventory size

Nearest county inventories outside MO (301 bridges here).

Madison County, IN · 301 bridges
Cedar County, IA · 301 bridges
Crawford County, IA · 301 bridges
Penobscot County, ME · 301 bridges

Similar average build year

Nearest mean year-built outside MO (1992 here).

Johnson County, KS · avg 1992 · 781 bridges
Wake County, NC · avg 1992 · 760 bridges
Benton County, AR · avg 1992 · 410 bridges
Cameron County, TX · avg 1992 · 355 bridges

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

All 301 Good 183 Fair 98 Poor 20

All bridges (301)

Sort:

Adair County Bridge Snapshot

Condition distribution

Adair County's Poor-condition bridges carry 4,563 vehicle crossings a day

14% of Adair County's bridges have passed the 50-year mark

One structure carries 57.7% of the county's Poor-condition bridge traffic

How Adair County compares with Missouri'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 (301)

CENTURY WAY

CHAPMAN WAY

SPERRY WAY

SWISHER RD

UNDERHILL LN

MULE TRAIN WAY

GIFFORD TRAIL

SWISHER RD

RT KK E

LINDERVILLE TRAIL

MO 6 E

BANKER RUN WAY

BERRY TRAIL

OKLAHOMA LN

MOCKINGBIRD HILL L

ARCHER TRAIL

OKLAHOMA TRAIL

RT K S

BANKER RUN WAY

DESOTO LN

FRONTIER LN

MANCHESTER TRAIL

SAND CRK BOTTOM RD

SHIBLEY RD

LAUREL LN

RT J S

PEACOCK RD

YOUNGSTOWN TRAIL

LOEFFLER STORE TRL

MO 11 S

FORT MADISON WAY

SHADOW WAY

EAST CENTER WAY

BANNER LN

MONTGOMERY WOODS T

APACHE WAY

MOCKINGBIRD HILL L

MORGAN WAY

CLAY WAY

BENTON WAY

BILLY CREEK TRAIL

PURE AIR TRAIL

CREST TRAIL

NEW ST

HORIZON TRAIL

MO 149 S

TITAN LN

TURKEY RUN TRAIL

WILLMATHSVILLE SCH

CALDWELL WAY

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