US Bridges

Mo 15 S over Rock CR

Fair

Knox County, Missouri · S 25 T 62 N R 12 W · Structure no. 5105

Built
1932
93 years old, rebuilt 1990
Condition
Fair
inspected November 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
158 ft
3 main spans
Daily traffic
1,025
2024 count
Owner
State
State Highway Agency

About this bridge

Mo 15 S over Rock CR is a steel stringer/multi-beam or girder carrying Mo 15 S over Rock CR in Knox County, Missouri. It was built in 1932 and reconstructed in 1990, so it is 93 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 1,025 vehicles a day, roughly 22% of them trucks, projected to reach 1,589 by 2044. The structure is 158 ft (48.2 m) long and 25 ft wide. If it were closed, the detour would be 21.7 mi (35 km).

Location

Open in Google Maps
CarriesMo 15 S
CrossesRock CR
LocationS 25 T 62 N R 12 W
RouteState Highway 15
CountyKnox County
StateMissouri
Coordinates40.14865, -92.17496
Functional classRural 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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionNovember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating31.7 US tons
Inventory rating17.9 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans3
Design loadH 15
Structure length158 ft (48.2 m)
Longest span52 ft (16 m)
Deck width25 ft (7.6 m)
Roadway width24 ft (7.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,025 (2024)
Projected traffic1,589 by 2044
Trucks22%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed21.7 mi (35 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 Mo 15 S over Rock CR built?

It was built in 1932, making it 93 years old in 2025. It was reconstructed in 1990.

What condition is Mo 15 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 2023.

How much traffic does Mo 15 S over Rock CR carry?

About 1,025 vehicles per day (2024 count), of which roughly 22% are trucks.

How long is Mo 15 S over Rock CR?

The structure is 158 ft (48.2 m) long with a longest span of 52 ft (16 m) and a deck 25 ft wide.

Who owns Mo 15 S over Rock CR?

It is owned by the State Highway Agency.