County profile · official public datasets

Shelby County, MO

108 public highway bridges tracked in the FHWA National Bridge Inventory: 28.7% rated Good, 56.5% Fair, 14.8% Poor.

108
Public bridges: 28.7%
Good condition: 14.8%
Poor condition

The verdict

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

Shelby County posts a higher-than-median Poor-condition share among rated counties in the state across mid-size county bridge inventory.

95th
of 115 on Poor share: 14.8%
Poor-condition share: 108
public highway bridges: 1977
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.

Shelby County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Shelby County ranks #95 of 115 Missouri counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 14.8%). Shelby County, Missouri contains 108 public highway bridges. Roughly 28.7% are rated “Good,” 56.5% “Fair,” and 14.8% “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

108

Public highway bridges in Shelby County

Good condition

28.7%

31 of 108 rated 7-9

Fair condition

56.5%

61 of 108 rated 5-6

Poor condition

14.8%

16 of 108 rated 4 or below

In-state Poor-share rank

#95 of 115

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

Condition distribution

Share of 108 NBI-tracked bridges by lowest applicable component rating.

Good

28.7% (31)

Fair

56.5% (61)

Poor

14.8% (16)

Shelby County's Poor-condition bridges carry 1,116 vehicle crossings a day

That is 2.2% of the county's reported daily bridge traffic on 14.8% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 70 crossings a day against 721 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 108 of 108 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

37% of Shelby County's bridges have passed the 50-year mark

40 of the 108 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 26.9% of the county's Poor-condition bridge traffic

RT K E over BLACK CR, built 1952, carries 300 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 16-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 1,116 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

2
1910s

6
1920s

5
1930s

14
1940s

2
1950s

6
1960s

4
1970s

5
1980s

5
1990s

25
2000s

15
2010s

15
2020s

4

What this shows Construction peaked in the 1990s, when 25 of the county's bridges still in the inventory were built, which is 23.1% of those with a recorded year. That cohort is now 25 to 34 years old in the 2024 inventory. Its average build year (1977) matches the Missouri average (1979).

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

The 5 Missouri counties nearest Shelby County in number of bridges, with their condition splits. Its 14.8% Poor share is the 5th-lowest of these 6. Its average build year of 1977 against a peer-group mean of 1970 is 7 years newer.

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

Bridge inventory size and condition shares for Shelby County and the 5 Missouri counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Dallas County	114	41.2%	52.6%	6.1%	1973
Cedar County	112	24.1%	50.9%	25%	1967
Shelby County (this page)	108	28.7%	56.5%	14.8%	1977
Morgan County	105	28.6%	61%	10.5%	1964
Pulaski County	104	21.2%	68.3%	10.6%	1975
Ste. Genevieve County	104	38.5%	51%	10.6%	1972

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

Similar inventory size

Nearest county inventories outside MO (108 bridges here).

Lassen County, CA · 108 bridges
Pulaski County, IL · 108 bridges
West Feliciana County, LA · 108 bridges
Brown County, MN · 108 bridges

Similar average build year

Nearest mean year-built outside MO (1977 here).

San Diego County, CA · avg 1977 · 1,632 bridges
King County, WA · avg 1977 · 1,238 bridges
Riverside County, CA · avg 1977 · 1,117 bridges
Shelby County, TN · avg 1977 · 1,077 bridges

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

All 108 Good 31 Fair 61 Poor 16

All bridges (108)

Sort:

Shelby County Bridge Snapshot

Condition distribution

Shelby County's Poor-condition bridges carry 1,116 vehicle crossings a day

37% of Shelby County's bridges have passed the 50-year mark

One structure carries 26.9% of the county's Poor-condition bridge traffic

How Shelby 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 (108)

COUNTY RD 520

COUNTY RD 301

COUNTY RD 514

COUNTY RD 474

MO 15 S

COUNTY RD 420

COUNTY RD 375

COUNTY RD 408

RT N S

RT E S

COUNTY RD 120

COUNTY RD 239

MO 15 S

RT T S

COUNTY RD 150

COUNTY RD 468

RT T S

RT T S

MO 151 S

COUNTY RD 432

COUNTY RD 464

RT A S

RT DD E

RT W S

RT M E

US 36 E

RT M E

COUNTY RD 118

COUNTY RD 159

COUNTY RD 255

COUNTY RD 352

COUNTY RD 474

COUNTY RD 516

COUNTY RD 227

COUNTY RD 227

MO 168 E

COUNTY RD 413

MO 168 E

COUNTY RD 322

US 36 W

COUNTY RD 017

MO 15 S

RT TT S

MO 168 E

GOLF COURSE DR

MO 168 E

MO 168 E

COUNTY RD 301

RT T S

COUNTY RD 353

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