US Bridges

Or 55 S over Rock CR

Fair

Jefferson County, Missouri · S 2009 T 42 N R 6 E · Structure no. 32293

Built
2008
17 years old
Condition
Fair
inspected November 2024
Type
Slab
Prestressed Concrete Continuous
Length
148 ft
3 main spans
Daily traffic
17,459
2024 count
Owner
State
State Highway Agency

About this bridge

Or 55 S over Rock CR is a prestressed concrete continuous slab carrying Or 55 S over Rock CR in Jefferson County, Missouri. It was built in 2008, so it is 17 years old, younger 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 17,459 vehicles a day, roughly 5% of them trucks, projected to reach 29,680 by 2044. The structure is 148 ft (45 m) long and 45 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesOr 55 S
CrossesRock CR
LocationS 2009 T 42 N R 6 E
RouteState Highway 55
CountyJefferson County
StateMissouri
Coordinates38.3768, -90.3808
Functional classUrban Minor Arterial

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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating66.5 US tons
Inventory rating39.7 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHL 93
Structure length148 ft (45 m)
Longest span55 ft (16.8 m)
Deck width45 ft (13.7 m)
Roadway width42 ft (12.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic17,459 (2024)
Projected traffic29,680 by 2044
Trucks5%
Lanes on structure3
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Or 55 S over Rock CR built?

It was built in 2008, making it 17 years old in 2025.

What condition is Or 55 S over 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 November 2024.

How much traffic does Or 55 S over Rock CR carry?

About 17,459 vehicles per day (2024 count), of which roughly 5% are trucks.

How long is Or 55 S over Rock CR?

The structure is 148 ft (45 m) long with a longest span of 55 ft (16.8 m) and a deck 45 ft wide.

Who owns Or 55 S over Rock CR?

It is owned by the State Highway Agency.