Total bridges
436
Public highway bridges in Clay County
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.
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
- 1900s 4
1900–1909
4 bridges
- 1910s 4
1910–1919
4 bridges
- 1920s 12
1920–1929
12 bridges
- 1930s 14
1930–1939
14 bridges
- 1940s 5
1940–1949
5 bridges
- 1950s
1950–1959
51 bridges
- 1960s
1960–1969
67 bridges
- 1970s
1970–1979
58 bridges
- 1980s
1980–1989
64 bridges
- 1990s
1990–1999
48 bridges
- 2000s
2000–2009
38 bridges
- 2010s
2010–2019
57 bridges
- 2020s 14
2020–2029
14 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).
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.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Jasper County | 471 | 42% | 46.9% | 11% | 1978 |
| Clay County (this page) | 436 | 38.1% | 55% | 6.9% | 1979 |
| Stoddard County | 434 | 43.1% | 53.2% | 3.7% | 1976 |
| St. Charles County | 417 | 32.4% | 64.3% | 3.4% | 1994 |
| Jefferson County | 411 | 33.6% | 63% | 3.4% | 1981 |
| Vernon County | 401 | 35.4% | 60.3% | 4.2% | 1988 |
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).
- Butte County, CA · 437 bridges
- Pinellas County, FL · 435 bridges
- Mercer County, PA · 438 bridges
- Licking County, OH · 439 bridges
Similar average build year
Nearest mean year-built outside MO (1979 here).
- Pima County, AZ · avg 1979 · 1,150 bridges
- Jefferson County, KY · avg 1979 · 662 bridges
- Spartanburg County, SC · avg 1979 · 638 bridges
- McPherson County, KS · avg 1979 · 586 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Good-condition bridges (166)
N AGNES ST
GoodOver: SHOAL CR
S 18 T 51 N R 32 W, Clay, MO
Built 2004 Load: 54.9 t ADT: 2,038
IS 29 S
GoodOver: RP MO210E TO IS29N RP
S 13 T 50 N R 33 W, Clay, MO
Built 2010 Load: 54.9 t ADT: 44,798
RT A S
GoodOver: FISHING RVR
S 19 T 52 N R 31 W, Clay, MO
Built 2010 Load: 57.6 t ADT: 3,625
NE 96TH ST (EB)
GoodOver: E FK OF SHOAL CR T
S 33 T 52 N R 32 W, Clay, MO
Built 2009 Load: 61.2 t ADT: 3,903
NE 144TH ST
GoodOver: WILLIAMS CR
S 4 T 52 N R 30 W, Clay, MO
Built 2009 Load: 62.1 t ADT: 65
US 69 S
GoodOver: BR WILLIAMS CR
S 13 T 53 N R 30 W, Clay, MO
Built 2012 Load: 64.8 t ADT: 7,586
GREENWOOD RD
GoodOver: FISHING RVR
S 26 T 52 N R 30 W, Clay, MO
Built 2021 Load: 67.5 t ADT: 102
RT DD E
GoodOver: WILKERSON CR
S 23 T 53 N R 33 W, Clay, MO
Built 2018 Load: 71.1 t ADT: 2,340
US 69 S
GoodOver: HOLMES CR
S 18 T 52 N R 30 W, Clay, MO
Built 1954 Load: 71.1 t ADT: 8,174
WB NE 96TH ST
GoodOver: E FK OF SHOAL CR T
S 33 T 52 N R 32 W, Clay, MO
Built 2012 Load: 74.7 t ADT: 3,788
NE 76TH ST
GoodOver: LIT SHOAL CR
S 14 T 51 N R 32 W, Clay, MO
Built 2013 Load: 78.3 t ADT: 5,934
AMORY RD
GoodOver: ROCKY BRANCH STR
S 2 T 52 N R 33 W, Clay, MO
Built 2018 Load: 81.0 t ADT: 300
MAIN ST E
GoodOver: ROSE BR
S 18 T 51 N R 30 W, Clay, MO
Built 2000 Load: 86.4 t ADT: 432
MT OLIVET RD
GoodOver: TRIB WILKERSON CR
S 17 T 52 N R 32 W, Clay, MO
Built 2020 Load: 86.4 t ADT: 760
NE STALEY RD
GoodOver: E FK SHOAL CR
S 30 T 52 N R 32 W, Clay, MO
Built 2009 Load: 99.9 t ADT: 3,034
MO 152 E
GoodOver: N BR OF BIG SHOAL
S 1 T 51 N R 33 W, Clay, MO
Built 1995 Load: 99.9 t ADT: 63,714
Read our methodology - how this data is sourced, computed, and verified.
Related
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.