County profile · official public datasets

Clay County, MO

436 public highway bridges tracked in the FHWA National Bridge Inventory: 38.1% rated Good, 55% Fair, 6.9% Poor.

436
Public bridges
38.1%
Good condition
6.9%
Poor condition

The verdict

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

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

Top 35%
lowest Poor share in state
6.9%
Poor-condition share
436
public highway bridges
1979
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.

Clay County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Clay County ranks #40 of 115 Missouri counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 6.9%). Clay County, Missouri contains 436 public highway bridges. Roughly 38.1% are rated “Good,” 55% “Fair,” and 6.9% “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

436

Public highway bridges in Clay County

Good condition

38.1%

166 of 436 rated 7-9

Fair condition

55%

240 of 436 rated 5-6

Poor condition

6.9%

30 of 436 rated 4 or below

In-state Poor-share rank

#40 of 115

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

Condition distribution

Share of 436 NBI-tracked bridges by lowest applicable component rating.

Good
38.1% (166)
Fair
55% (240)
Poor
6.9% (30)

Clay County's Poor-condition bridges carry 183,835 vehicle crossings a day

That is 3.6% of the county's reported daily bridge traffic on 6.9% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 6,128 crossings a day against 9,927 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 436 of 436 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

42.4% of Clay County's bridges have passed the 50-year mark

185 of the 436 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 38.1% 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 36.9% of the county's Poor-condition bridge traffic

IS 35 S over ROCK CR, built 1956, carries 67,766 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 30-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 183,835 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

When Clay County's bridges were built

436 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 1960s, when 67 of the county's bridges still in the inventory were built, which is 15.4% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year (1979) matches the Missouri average (1979).

Source FHWA National Bridge Inventory (year built) As of 2024 NBI release

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

The 5 Missouri counties nearest Clay County in number of bridges, with their condition splits. Its 6.9% Poor share is the 5th-lowest of these 6. Its average build year of 1979 against a peer-group mean of 1983 is in line with the group.

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

Bridge inventory size and condition shares for Clay County and the 5 Missouri counties closest to it in inventory size
County Bridges Poor
Jasper County 471 11%
Clay County (this page) 436 6.9%
Stoddard County 434 3.7%
St. Charles County 417 3.4%
Jefferson County 411 3.4%
Vernon County 401 4.2%

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

Similar inventory size

Nearest county inventories outside MO (436 bridges here).

Similar average build year

Nearest mean year-built outside MO (1979 here).

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

All 436 Good 166 Fair 240 Poor 30

Good-condition bridges (166)

MO 152 W

Good

Over: MO 1

S 8 T 51 N R 32 W, Clay, MO

Built 1997 Load: 42.3 t ADT: 30,286

US 169 S

Good

Over: CST NW 68TH ST

S 22 T 51 N R 33 W, Clay, MO

Built 2000 Load: 43.2 t ADT: 24,902

OR 210 E

Good

Over: SEARCY CR

S 8 T 50 N R 32 W, Clay, MO

Built 1970 Load: 43.2 t ADT: 2,480

NE 136TH TERRACE

Good

Over: WILLIAMS CR

S 4 T 52 N R 30 W, Clay, MO

Built 2006 Load: 43.2 t ADT: 65

MO 92 E

Good

Over: CLEAR CR

S 35 T 53 N R 31 W, Clay, MO

Built 2008 Load: 43.2 t ADT: 8,530

IS 29 S

Good

Over: CST 16TH AVE

S 13 T 50 N R 33 W, Clay, MO

Built 2010 Load: 43.2 t ADT: 53,349

MO 291 S

Good

Over: IS 35

S 1 T 51 N R 32 W, Clay, MO

Built 2013 Load: 43.2 t ADT: 29,150

RP IS35S TO MO152E

Good

Over: IS 35

S 11 T 51 N R 32 W, Clay, MO

Built 2019 Load: 43.2 t ADT: 6,229

IS 35 S

Good

Over: MILL CR

S 28 T 51 N R 32 W, Clay, MO

Built 1958 Load: 43.2 t ADT: 64,227

SCHOOL FIELD RD

Good

Over: WILLIAMS CR

S 33 T 53 N R 30 W, Clay, MO

Built 2013 Load: 44.1 t ADT: 195

FLINTLOCK RD

Good

Over: TRIB TO LT SHOAL C

S 14 T 51 N R 32 W, Clay, MO

Built 2004 Load: 44.1 t ADT: 10,558

US 169 N

Good

Over: CST NW 68TH ST

S 22 T 51 N R 33 W, Clay, MO

Built 1985 Load: 45.0 t ADT: 30,920

MO 152 E

Good

Over: IS 35

S 11 T 51 N R 32 W, Clay, MO

Built 2019 Load: 45.0 t ADT: 57,287

148TH ST

Good

Over: CARROLL CR

S 31 T 53 N R 30 W, Clay, MO

Built 2020 Load: 45.0 t ADT: 250

RT A S

Good

Over: BRUSHY CR

S 7 T 52 N R 31 W, Clay, MO

Built 1997 Load: 45.0 t ADT: 3,625

NE 172ND STREET

Good

Over: CARROLL CRK

S 18 T 53 N R 30 W, Clay, MO

Built 2017 Load: 45.9 t ADT: 64

N HOME AVE

Good

Over: FISHING RVR

S 23 T 52 N R 32 W, Clay, MO

Built 2006 Load: 46.8 t ADT: 116

NE 180TH ST

Good

Over: OWEN BR

S 11 T 53 N R 33 W, Clay, MO

Built 2008 Load: 46.8 t ADT: 380

MO 92 E

Good

Over: WILLIAMS CR

S 28 T 53 N R 30 W, Clay, MO

Built 2010 Load: 46.8 t ADT: 8,530

NW TIFFANY SPRINGS

Good

Over: US 169

S 35 T 52 N R 33 W, Clay, MO

Built 2012 Load: 46.8 t ADT: 2,320

IS 35 N

Good

Over: CST POE AVE

S 28 T 51 N R 32 W, Clay, MO

Built 2015 Load: 46.8 t ADT: 31,685

IS 35 S

Good

Over: CST POE AVE

S 28 T 51 N R 32 W, Clay, MO

Built 2015 Load: 46.8 t ADT: 32,542

US 69 S

Good

Over: THORNTON MILL CR

S 28 T 51 N R 32 W, Clay, MO

Built 1996 Load: 46.8 t ADT: 8,676

US 69 S

Good

Over: SHOAL CR

S 27 T 51 N R 32 W, Clay, MO

Built 1996 Load: 46.8 t ADT: 10,298

US 69 S

Good

Over: FISHING RVR

S 18 T 52 N R 30 W, Clay, MO

Built 1954 Load: 46.8 t ADT: 8,174

US 69 S

Good

Over: WILLIAMS CR

S 9 T 52 N R 30 W, Clay, MO

Built 1954 Load: 46.8 t ADT: 9,084

N CHOUTEAU TRAFFIC

Good

Over: BUCKEYE CR

S 7 T 50 N R 32 W, Clay, MO

Built 2012 Load: 47.7 t ADT: 14,557

188TH ST

Good

Over: NEW HOPE CR

S 6 T 53 N R 30 W, Clay, MO

Built 2021 Load: 47.7 t ADT: 250

LANCASTER RD

Good

Over: BR OF FISHING RVR

S 26 T 52 N R 31 W, Clay, MO

Built 2023 Load: 47.7 t ADT: 187

MO 210 E

Good

Over: BNSF RR

S 10 T 50 N R 32 W, Clay, MO

Built 1999 Load: 48.6 t ADT: 8,244

RT KK E

Good

Over: OWENS BR

S 15 T 53 N R 33 W, Clay, MO

Built 2010 Load: 48.6 t ADT: 913

NB N BRIGHTON

Good

Over: MILL CR

S 32 T 51 N R 32 W, Clay, MO

Built 2009 Load: 48.6 t ADT: 3,152

US 169 S

Good

Over: US 69

S 34 T 51 N R 33 W, Clay, MO

Built 1965 Load: 49.5 t ADT: 18,781

SUMMERSET RD

Good

Over: BR OF FISHING RVR

S 13 T 52 N R 31 W, Clay, MO

Built 2007 Load: 49.5 t ADT: 960

SB N BRIGHTON AVE

Good

Over: MILL CR

S 32 T 51 N R 32 W, Clay, MO

Built 2011 Load: 49.5 t ADT: 3,125

MO 210 E

Good

Over: DM&E RR

S 11 T 50 N R 32 W, Clay, MO

Built 2014 Load: 49.5 t ADT: 8,244

MO 33 S

Good

Over: CLEAR CR

S 22 T 53 N R 31 W, Clay, MO

Built 2000 Load: 50.4 t ADT: 13,368

PETTY RD

Good

Over: FISHING RVR

S 3 T 52 N R 31 W, Clay, MO

Built 2000 Load: 50.4 t ADT: 152

MO 210 E

Good

Over: ROSE BR

S 18 T 51 N R 30 W, Clay, MO

Built 1997 Load: 52.2 t ADT: 10,160

MO 152 E

Good

Over: LIT SHOAL CR

S 10 T 51 N R 32 W, Clay, MO

Built 1982 Load: 52.2 t ADT: 46,524

US 69 N

Good

Over: BNSF RR

S 28 T 52 N R 31 W, Clay, MO

Built 2012 Load: 52.2 t ADT: 10,622

N FLINTLOCK RD S

Good

Over: IS 35 CST S STEWART RD

S 14 T 51 N R 32 W, Clay, MO

Built 2013 Load: 52.2 t ADT: 17,739

NE 76TH ST

Good

Over: LITTLE SHOAL CREEK

S 14 T 51 N R 32 W, Clay, MO

Built 2013 Load: 52.2 t ADT: 6,233

RP MO152W TO MAPLE

Good

Over: N BR OF BIG SHOAL

S 1 T 51 N R 33 W, Clay, MO

Built 2002 Load: 52.2 t ADT: 2,154

RP MAPLE WOODS PKW

Good

Over: N BR OF BIG SHOAL

S 1 T 51 N R 33 W, Clay, MO

Built 2006 Load: 52.2 t ADT: 2,479

SHANKS RD

Good

Over: MUDDY FK HOLT CR

S 35 T 54 N R 31 W, Clay, MO

Built 1999 Load: 53.1 t ADT: 249

RT N N

Good

Over: FISHING RVR

S 36 T 52 N R 30 W, Clay, MO

Built 2010 Load: 53.1 t ADT: 1,026

NE 53RD TER E

Good

Over: IS 435

S 34 T 51 N R 32 W, Clay, MO

Built 2021 Load: 53.1 t ADT: 7,522

US 169 N

Good

Over: US 69

S 334 T 51 N R 33 W, Clay, MO

Built 1965 Load: 54.0 t ADT: 17,409

MO 1 S

Good

Over: DRAIN DTCH

S 13 T 50 N R 33 W, Clay, MO

Built 2014 Load: 54.0 t ADT: 5,772

Read our methodology - how this data is sourced, computed, and verified.

Related

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Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainBridges

Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.