County profile · official public datasets

Lewis County, MO

171 public highway bridges tracked in the FHWA National Bridge Inventory: 28.7% rated Good, 66.1% Fair, 5.3% Poor.

171
Public bridges: 28.7%
Good condition: 5.3%
Poor condition

The verdict

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

Lewis 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 21%
lowest Poor share in state: 5.3%
Poor-condition share: 171
public highway bridges: 1990
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.

Lewis County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Lewis County ranks #24 of 115 Missouri counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 5.3%). Lewis County, Missouri contains 171 public highway bridges. Roughly 28.7% are rated “Good,” 66.1% “Fair,” and 5.3% “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

171

Public highway bridges in Lewis County

Good condition

28.7%

49 of 171 rated 7-9

Fair condition

66.1%

113 of 171 rated 5-6

Poor condition

5.3%

9 of 171 rated 4 or below

In-state Poor-share rank

#24 of 115

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

Condition distribution

Share of 171 NBI-tracked bridges by lowest applicable component rating.

Good

28.7% (49)

Fair

66.1% (113)

Poor

5.3% (9)

Lewis County's Poor-condition bridges carry 368 vehicle crossings a day

That is 0.2% of the county's reported daily bridge traffic on 5.3% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 41 crossings a day against 666 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 171 of 171 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

22.8% of Lewis County's bridges have passed the 50-year mark

39 of the 171 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 28.7% 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 34.8% of the county's Poor-condition bridge traffic

RT H S over MID FABIUS RVR, built 1961, carries 128 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 368 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

2
1910s

5
1920s

1
1930s

4
1940s

3
1950s

3
1960s

7
1970s

14
1980s

9
1990s

53
2000s

42
2010s

20
2020s

8

What this shows Construction peaked in the 1990s, when 53 of the county's bridges still in the inventory were built, which is 31% of those with a recorded year. That cohort is now 25 to 34 years old in the 2024 inventory. Its average build year is 1990, 11 years newer than the Missouri average of 1979.

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

The 5 Missouri counties nearest Lewis County in number of bridges, with their condition splits. Its 5.3% Poor share is the 2nd-lowest of these 6. Its average build year of 1990 against a peer-group mean of 1978 is 12 years newer.

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

Bridge inventory size and condition shares for Lewis County and the 5 Missouri counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Clark County	178	38.2%	53.9%	7.9%	1986
Lewis County (this page)	171	28.7%	66.1%	5.3%	1990
Holt County	167	38.3%	46.7%	15%	1974
Knox County	167	34.7%	61.1%	4.2%	1987
Barry County	166	23.5%	61.4%	15.1%	1973
St. Francois County	165	38.2%	51.5%	10.3%	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 Lewis 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 Lewis County, both outside Missouri so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside MO (171 bridges here).

Crenshaw County, AL · 171 bridges
Miami County, IN · 171 bridges
Lincoln County, LA · 171 bridges
Sanilac County, MI · 171 bridges

Similar average build year

Nearest mean year-built outside MO (1990 here).

Maricopa County, AZ · avg 1990 · 2,847 bridges
Tarrant County, TX · avg 1990 · 2,617 bridges
Fairfax County, VA · avg 1990 · 751 bridges
Guilford County, NC · avg 1990 · 736 bridges

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

All 171 Good 49 Fair 113 Poor 9

Good-condition bridges (49)

Sort:

Lewis County Bridge Snapshot

Condition distribution

Lewis County's Poor-condition bridges carry 368 vehicle crossings a day

22.8% of Lewis County's bridges have passed the 50-year mark

One structure carries 34.8% of the county's Poor-condition bridge traffic

How Lewis 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

Good-condition bridges (49)

COUNTY RD 248

COUNTY RD 357

SUNFLOWER ST E

RT E E

COUNTY RD 456

RT V E

RT N S

COUNTY RD 261

COUNTY RD 224

RT C E

COUNTY RD 490

US 61 S

COUNTY RD 228

RT B S

COUNTY RD 587

HAWTHORN ST (508)

MO 156 E

COUNTY RD 588

RT K E

RT E E

COUNTY RD 419

COUNTY RD 297

COUNTY RD 436

COUNTY RD 297

RT J S

COUNTY RD 403

RT E E

COUNTY RD 242

COUNTY RD 575

RT E E

RT C E

COUNTY RD 374

COUNTY RD 357

RT C E

MO 156 E

COUNTY RD 536

MO 156 E

CR 433

CR 305

US 61 N

COUNTY RD 585

MO 16 E

MO 16 E

COUNTY RD 226

MO 16 E

COUNTY RD 336

US 61 N

COUNTY RD 412

COUNTY RD 585

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