County profile · official public datasets

Audrain County, MO

314 public highway bridges tracked in the FHWA National Bridge Inventory: 41.4% rated Good, 53.8% Fair, 4.8% Poor.

314
Public bridges: 41.4%
Good condition: 4.8%
Poor condition

The verdict

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

Audrain County pairs a top-quartile lowest Poor-condition share among rated counties in the state with a newer average build year than the state inventory.

Top 17%
lowest Poor share in state: 4.8%
Poor-condition share: 314
public highway bridges: 1987
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.

Audrain County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Audrain County ranks #19 of 115 Missouri counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 4.8%). Audrain County, Missouri contains 314 public highway bridges. Roughly 41.4% are rated “Good,” 53.8% “Fair,” and 4.8% “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

314

Public highway bridges in Audrain County

Good condition

41.4%

130 of 314 rated 7-9

Fair condition

53.8%

169 of 314 rated 5-6

Poor condition

4.8%

15 of 314 rated 4 or below

In-state Poor-share rank

#19 of 115

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

Condition distribution

Share of 314 NBI-tracked bridges by lowest applicable component rating.

Good

41.4% (130)

Fair

53.8% (169)

Poor

4.8% (15)

Audrain County's Poor-condition bridges carry 20,284 vehicle crossings a day

That is 10.4% of the county's reported daily bridge traffic on 4.8% of its bridges: Poor-condition structures carry more traffic than their share of the inventory. Each Poor bridge averages 1,352 crossings a day against 372 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 314 of 314 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

21.7% of Audrain County's bridges have passed the 50-year mark

68 of the 314 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 41.4% 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 29.7% of the county's Poor-condition bridge traffic

US 54 W over BEAVER DAM CR, built 1927, carries 6,023 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 15-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 20,284 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

2
1920s

9
1930s

16
1940s

4
1950s

16
1960s

15
1970s

16
1980s

34
1990s

89
2000s

75
2010s

35
2020s

3

What this shows Construction peaked in the 1990s, when 89 of the county's bridges still in the inventory were built, which is 28.3% of those with a recorded year. That cohort is now 25 to 34 years old in the 2024 inventory. Its average build year is 1987, 8 years newer than the Missouri average of 1979.

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

The 5 Missouri counties nearest Audrain County in number of bridges, with their condition splits. Its 4.8% Poor share is the 1st-lowest of these 6. Its average build year of 1987 against a peer-group mean of 1981 is 6 years newer.

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

Bridge inventory size and condition shares for Audrain County and the 5 Missouri counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Bates County	319	22.6%	70.2%	7.2%	1977
Audrain County (this page)	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	301	60.8%	32.6%	6.6%	1992
Newton County	300	39%	54.3%	6.7%	1978

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

Similar inventory size

Nearest county inventories outside MO (314 bridges here).

Jackson County, AL · 314 bridges
Cloud County, KS · 314 bridges
Douglas County, KS · 314 bridges
Franklin County, MA · 314 bridges

Similar average build year

Nearest mean year-built outside MO (1987 here).

Ellis County, TX · avg 1987 · 691 bridges
St. Louis County, MN · avg 1987 · 663 bridges
Palm Beach County, FL · avg 1987 · 610 bridges
Dane County, WI · avg 1987 · 590 bridges

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

All 314 Good 130 Fair 169 Poor 15

All bridges (314)

Sort:

Audrain County Bridge Snapshot

Condition distribution

Audrain County's Poor-condition bridges carry 20,284 vehicle crossings a day

21.7% of Audrain County's bridges have passed the 50-year mark

One structure carries 29.7% of the county's Poor-condition bridge traffic

How Audrain 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 (314)

JEFFERSON ST

CRAIG ST

CLARK ST

RT O S

RT T E

RT B S

COUNTY RD 209

COUNTY RD 435

RT J E

RT K E

RT BB E

RT C S

MO 15 S

US 54 W

COUNTY RD 353

US 54 E

COUNTY RD 165

COUNTY RD 132

COUNTY RD 221

COUNTY RD 225

COUNTY RD 395

COUNTY RD 957

COUNTY RD 948

COUNTY RD 353

COUNTY RD 408

COUNTY RD 927

COUNTY RD 917

COUNTY RD 852

COUNTY RD 725

COUNTY RD 372

COUNTY RD 335

COUNTY RD 448

COUNTY RD 424

COUNTY RD 489

COUNTY RD 609

COUNTY RD 591

COUNTY RD 681

COUNTY RD 744

COUNTY RD 949

CALHOUN ST

WOODLAWN ST

COUNTY RD 516

COUNTY RD 948

COUNTY RD 609

COUNTY RD 368

RT W S

COUNTY RD 256

COUNTY RD 556

MO 19 S

RT B S

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