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

Poor-condition bridges (30)

JOHNSON RD

Poor

Over: BR LIT SHOAL CR

S 13 T 51 N R 32 W, Clay, MO

Built 1940 Load: 0.0 t ADT: 250

OLD 210 HWY

Poor

Over: RUSH CR

S 26 T 51 N R 31 W, Clay, MO

Built 1946 Load: 0.0 t ADT: 267

3RD ST

Poor

Over: FISHING RVR

S 17 T 52 N R 30 W, Clay, MO

Built 1969 Load: 0.0 t ADT: 400

RICHFIELD RD

Poor

Over: RUSH CR

S 9 T 51 N R 31 W, Clay, MO

Built 1920 Load: 0.9 t ADT: 900

SIXTH ST

Poor

Over: SMALL CR

S 9 T 50 N R 32 W, Clay, MO

Built 2006 Load: 2.7 t ADT: 10

164TH ST

Poor

Over: BR OF WILLIAMS CR

S 23 T 53 N R 30 W, Clay, MO

Built 1945 Load: 5.4 t ADT: 314

OLD 210 HWY

Poor

Over: RUSH CR

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

Built 1940 Load: 7.2 t ADT: 267

GARLAND AVE

Poor

Over: DRY FK FISHING RVR

S 12 T 52 N R 30 W, Clay, MO

Built 1917 Load: 9.0 t ADT: 450

LONG RIDGE RD

Poor

Over: BR OF FISHING RVR

S 25 T 52 N R 31 W, Clay, MO

Built 1935 Load: 9.0 t ADT: 225

NE 143RD TERRACE

Poor

Over: BR OF FISHING RVR

S 1 T 52 N R 30 W, Clay, MO

Built 1935 Load: 9.9 t ADT: 1,000

74TH ST

Poor

Over: RUSH CR

S 15 T 51 N R 31 W, Clay, MO

Built 1950 Load: 11.7 t ADT: 120

STOCKDALE RD

Poor

Over: CANADIAN PACIFIC R

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

Built 1930 Load: 12.6 t ADT: 600

MARILYNN ST

Poor

Over: CATES BR

S 20 T 51 N R 31 W, Clay, MO

Built 1960 Load: 12.6 t ADT: 250

ANTIOCH RD

Poor

Over: ROCK CR

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

Built 1920 Load: 14.4 t ADT: 3,371

178TH ST

Poor

Over: NEW HOPE CR

S 12 T 53 N R 31 W, Clay, MO

Built 1955 Load: 16.2 t ADT: 216

SHERRILL ST

Poor

Over: CATES BR

S 20 T 51 N R 31 W, Clay, MO

Built 1900 Load: 16.2 t ADT: 250

172ND ST

Poor

Over: NEW HOPE CR

S 14 T 53 N R 31 W, Clay, MO

Built 1919 Load: 17.1 t ADT: 109

ENDICOTT RD

Poor

Over: BR OF CARROLL CR

S 9 T 53 N R 30 W, Clay, MO

Built 1945 Load: 17.1 t ADT: 502

144TH ST

Poor

Over: ROCK CR

S 5 T 52 N R 31 W, Clay, MO

Built 1968 Load: 17.1 t ADT: 325

WALKER RD

Poor

Over: ROCK CR

S 7 T 50 N R 33 W, Clay, MO

Built 1975 Load: 18.9 t ADT: 500

RAYMOND HALL RD

Poor

Over: CLEAR CR

S 23 T 53 N R 31 W, Clay, MO

Built 1980 Load: 18.9 t ADT: 679

WATKINS RD

Poor

Over: BR OF WILLIAMS CR

S 34 T 53 N R 30 W, Clay, MO

Built 1986 Load: 32.4 t ADT: 105

N THOMPSON AVE

Poor

Over: FK OF FISHING RVR

S 1 T 52 N R 30 W, Clay, MO

Built 1990 Load: 32.4 t ADT: 90

SP 69 S

Poor

Over: IS 35

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

Built 1954 Load: 33.3 t ADT: 1,902

IS 29 N

Poor

Over: RP US169S TO IS29S US 1

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

Built 1957 Load: 34.2 t ADT: 54,703

US 169 N

Poor

Over: BNSF RR

S 11 T 50 N R 33 W, Clay, MO

Built 1956 Load: 36.0 t ADT: 19,434

MO 33 S

Poor

Over: CR

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

Built 1927 Load: 45.9 t ADT: 6,459

BURRIS RD

Poor

Over: TRIB OF MUDDY FK

S 35 T 54 N R 33 W, Clay, MO

Built 1996 Load: 51.3 t ADT: 157

IS 435 S

Poor

Over: FK OF WILKERSON CR

S 14 T 52 N R 33 W, Clay, MO

Built 1983 Load: 52.2 t ADT: 22,214

IS 35 S

Poor

Over: ROCK CR

S 1 T 50 N R 33 W, Clay, MO

Built 1956 Load: 99.9 t ADT: 67,766

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.