US Bridges

County RD NW 900 over Trib of Monegaw CR

PoorPosted for load

St. Clair County, Missouri · S 8 T 39 N R 28 W · Structure no. 16688

Built
1965
60 years old
Condition
Poor
inspected December 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
40 ft
1 main span
Daily traffic
20
2023 count
Owner
County
County Highway Agency

About this bridge

County RD NW 900 over Trib of Monegaw CR is a steel stringer/multi-beam or girder carrying County RD NW 900 over Trib of Monegaw CR in St. Clair County, Missouri. It was built in 1965, so it is 60 years old, older than the Missouri average of 45.1 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 3 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. 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 40 ft (12.2 m) long and 17 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

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CarriesCounty RD NW 900
CrossesTrib of Monegaw CR
LocationS 8 T 39 N R 28 W
RouteCounty Highway 129
CountySt. Clair County
StateMissouri
Coordinates38.16117, -94.0216
Functional classRural Local

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure3 SeriousLoss of section, deterioration, spalling or scour have seriously affected primary structural components.
Substructure7 GoodSome minor problems.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionDecember 2024
Inspection intervalevery 12 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation2: Basically intolerable, requiring high priority of replacement
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment6: Equal to present minimum criteria
Operating rating4 US tons
Inventory rating2 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadOther
Structure length40 ft (12.2 m)
Longest span39 ft (11.9 m)
Deck width17 ft (5.1 m)
Roadway width17 ft (5.1 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 closed5 mi (8 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byOther Local Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$344,000 (2025 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was County RD NW 900 over Trib of Monegaw CR built?

It was built in 1965, making it 60 years old in 2025.

What condition is County RD NW 900 over Trib of Monegaw CR in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in December 2024.

How much traffic does County RD NW 900 over Trib of Monegaw CR carry?

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

How long is County RD NW 900 over Trib of Monegaw CR?

The structure is 40 ft (12.2 m) long with a longest span of 39 ft (11.9 m) and a deck 17 ft wide.

Who owns County RD NW 900 over Trib of Monegaw CR?

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