US Bridges

Old Antonia RD over Trib of Rock CR

Fair

Jefferson County, Missouri · S 2005 T 42 N R 6 E · Structure no. 34989

Built
1975
50 years old
Condition
Fair
inspected February 2025
Type
Culvert
Concrete
Length
21 ft
1 main span
Daily traffic
8,000
2023 count
Owner
County
County Highway Agency

About this bridge

Old Antonia RD over Trib of Rock CR is a concrete culvert carrying Old Antonia RD over Trib of Rock CR in Jefferson County, Missouri. It was built in 1975, so it is 50 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 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 8,000 vehicles a day, roughly 5% of them trucks, projected to reach 13,600 by 2043. The structure is 21 ft (6.3 m) long and 26 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesOld Antonia RD
CrossesTrib of Rock CR
LocationS 2005 T 42 N R 6 E
RouteCounty Highway 0
CountyJefferson County
StateMissouri
Coordinates38.37231, -90.38803
Functional classUrban Collector

Condition and inspection

Fair

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

ComponentRatingMeaning
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionFebruary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating26.8 US tons
Inventory rating17.9 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans1
Design loadHS 20
Structure length21 ft (6.3 m)
Longest span21 ft (6.3 m)
Deck width26 ft (7.9 m)
Roadway width24 ft (7.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic8,000 (2023)
Projected traffic13,600 by 2043
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$153,000 (2025 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Old Antonia RD over Trib of Rock CR built?

It was built in 1975, making it 50 years old in 2025.

What condition is Old Antonia RD over Trib of Rock 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 February 2025.

How much traffic does Old Antonia RD over Trib of Rock CR carry?

About 8,000 vehicles per day (2023 count), of which roughly 5% are trucks.

How long is Old Antonia RD over Trib of Rock CR?

The structure is 21 ft (6.3 m) long with a longest span of 21 ft (6.3 m) and a deck 26 ft wide.

Who owns Old Antonia RD over Trib of Rock CR?

It is owned by the County Highway Agency.