County profile · official public datasets

Platte County, MO

285 public highway bridges tracked in the FHWA National Bridge Inventory: 38.9% rated Good, 55.1% Fair, 6% Poor.

285
Public bridges: 38.9%
Good condition: 6%
Poor condition

The verdict

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

Platte 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 24%
lowest Poor share in state: 6%
Poor-condition share: 285
public highway bridges: 1985
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.

Platte County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Platte County ranks #28 of 115 Missouri counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 6%). Platte County, Missouri contains 285 public highway bridges. Roughly 38.9% are rated “Good,” 55.1% “Fair,” and 6% “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

285

Public highway bridges in Platte County

Good condition

38.9%

111 of 285 rated 7-9

Fair condition

55.1%

157 of 285 rated 5-6

Poor condition

17 of 285 rated 4 or below

In-state Poor-share rank

#28 of 115

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

Condition distribution

Share of 285 NBI-tracked bridges by lowest applicable component rating.

Good

38.9% (111)

Fair

55.1% (157)

Poor

6% (17)

Platte County's Poor-condition bridges carry 81,999 vehicle crossings a day

That is 3% of the county's reported daily bridge traffic on 6% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 4,823 crossings a day against 9,101 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 285 of 285 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

33.3% of Platte County's bridges have passed the 50-year mark

95 of the 285 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 38.9% 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 44.9% of the county's Poor-condition bridge traffic

IS 29 S over OWL CR, built 1958, carries 36,821 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 17-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 81,999 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1910s

1
1920s

4
1930s

10
1940s

1
1950s

25
1960s

33
1970s

35
1980s

52
1990s

24
2000s

42
2010s

47
2020s

11

What this shows Construction peaked in the 1980s, when 52 of the county's bridges still in the inventory were built, which is 18.2% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year is 1985, 6 years newer than the Missouri average of 1979.

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

The 5 Missouri counties nearest Platte County in number of bridges, with their condition splits. Its 6% Poor share is the 2nd-lowest of these 6. Its average build year of 1985 against a peer-group mean of 1984 is in line with the group.

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

Bridge inventory size and condition shares for Platte County and the 5 Missouri counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Adair County	301	60.8%	32.6%	6.6%	1992
Newton County	300	39%	54.3%	6.7%	1978
Macon County	291	42.6%	49.8%	7.6%	1986
Chariton County	288	53.5%	35.1%	11.5%	1976
Platte County (this page)	285	38.9%	55.1%	6%	1985
New Madrid County	282	53.2%	44.7%	2.1%	1986

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

Similar inventory size

Nearest county inventories outside MO (285 bridges here).

Washington County, LA · 285 bridges
Robeson County, NC · 285 bridges
Haywood County, NC · 286 bridges
Bryan County, OK · 286 bridges

Similar average build year

Nearest mean year-built outside MO (1985 here).

Hillsborough County, FL · avg 1985 · 840 bridges
Lancaster County, NE · avg 1985 · 661 bridges
Nueces County, TX · avg 1985 · 528 bridges
Grayson County, TX · avg 1985 · 513 bridges

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

All 285 Good 111 Fair 157 Poor 17

Fair-condition bridges (157)

Sort:

Platte County Bridge Snapshot

Condition distribution

Platte County's Poor-condition bridges carry 81,999 vehicle crossings a day

33.3% of Platte County's bridges have passed the 50-year mark

One structure carries 44.9% of the county's Poor-condition bridge traffic

How Platte 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

Fair-condition bridges (157)

LANTER LN

HOUSTON LAKE DR

BROWN RD

OLD PIKE RD E

MO 371 S

NW COOKINGHAM DR E

N BLUFF RD

RUNNING HORSE

49TH ST

WOODRUFF RD

RT N S

RT B S

COOKINGHAM DR

OR 9 S

MO 45 S

RT P S

RT E E

RT V S

NEW MARKET RD E

NORTH AMERICAN AVE

IS 29 S

NW 75TH ST TERR

RP NW GATEWAY AVE

RT P S

PARIS ST

MO 92 E

BERN ST

RT C S

IS 435 S

IS 435 N

NAYLOR RD

RT N S

IS 29 S

IS 29 N

RT H S

IS 635 S

IS 29 S

IS 29 N

IS 635 N

RIVER RD

WILLIAMS RD EAST

COCKRIEL RD

MARTIN RD

RIVER RD

IS 29 S

IS 29 N

PARADISE VALLEY RD

MO 45 S

IS 435 S

IS 435 N

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