US Bridges

County RD NW 1000 over Trib of Coopers CR

FairPosted for load

St. Clair County, Missouri · S 4 T 39 N R 26 W · Structure no. 16460

Built
1940
85 years old, rebuilt 1960
Condition
Fair
inspected December 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
24 ft
1 main span
Daily traffic
20
2023 count
Owner
County
County Highway Agency

About this bridge

County RD NW 1000 over Trib of Coopers CR is a steel stringer/multi-beam or girder carrying County RD NW 1000 over Trib of Coopers CR in St. Clair County, Missouri. It was built in 1940 and reconstructed in 1960, so it is 85 years old, older than the Missouri average of 45.1 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. Its operating status is: posted for load restriction.

It carries about 20 vehicles a day, roughly 10% of them trucks, projected to reach 24 by 2043. The structure is 24 ft (7.3 m) long and 16 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

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CarriesCounty RD NW 1000
CrossesTrib of Coopers CR
LocationS 4 T 39 N R 26 W
RouteCounty Highway 121
CountySt. Clair County
StateMissouri
Coordinates38.168, -93.79135
Functional classRural Local

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionDecember 2023
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating25.8 US tons
Inventory rating14.9 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadOther
Structure length24 ft (7.3 m)
Longest span23 ft (7 m)
Deck width16 ft (4.9 m)
Roadway width16 ft (4.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic20 (2023)
Projected traffic24 by 2043
Trucks10%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byOther Local Agency
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$255,000 (2025 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was County RD NW 1000 over Trib of Coopers CR built?

It was built in 1940, making it 85 years old in 2025. It was reconstructed in 1960.

What condition is County RD NW 1000 over Trib of Coopers CR in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in December 2023.

How much traffic does County RD NW 1000 over Trib of Coopers CR carry?

About 20 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is County RD NW 1000 over Trib of Coopers CR?

The structure is 24 ft (7.3 m) long with a longest span of 23 ft (7 m) and a deck 16 ft wide.

Who owns County RD NW 1000 over Trib of Coopers CR?

It is owned by the County Highway Agency and maintained by the Other Local Agency.