US Bridges

County RD 124 over Rock CR

FairPosted for load

Knox County, Missouri · S 34 T 62 N R 12 W · Structure no. 16551

Built
1985
40 years old
Condition
Fair
inspected August 2023
Type
Girder and Floorbeam System
Steel
Length
67 ft
1 main span
Daily traffic
35
2024 count
Owner
County
County Highway Agency

About this bridge

County RD 124 over Rock CR is a steel girder and floorbeam system carrying County RD 124 over Rock CR in Knox County, Missouri. It was built in 1985, so it is 40 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 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 35 vehicles a day, roughly 10% of them trucks, projected to reach 44 by 2044. The structure is 67 ft (20.4 m) long and 25 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

Location

Open in Google Maps
CarriesCounty RD 124
CrossesRock CR
LocationS 34 T 62 N R 12 W
RouteCounty Highway 124
CountyKnox County
StateMissouri
Coordinates40.13064, -92.21239
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating32.7 US tons
Inventory rating19.8 US tons

Structure

Structure typeGirder and Floorbeam System
MaterialSteel
DeckWood or timber
Main spans1
Design loadOther
Structure length67 ft (20.4 m)
Longest span64 ft (19.5 m)
Deck width25 ft (7.7 m)
Roadway width24 ft (7.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic35 (2024)
Projected traffic44 by 2044
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.1 mi (13 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was County RD 124 over Rock CR built?

It was built in 1985, making it 40 years old in 2025.

What condition is County RD 124 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 August 2023.

How much traffic does County RD 124 over Rock CR carry?

About 35 vehicles per day (2024 count), of which roughly 10% are trucks.

How long is County RD 124 over Rock CR?

The structure is 67 ft (20.4 m) long with a longest span of 64 ft (19.5 m) and a deck 25 ft wide.

Who owns County RD 124 over Rock CR?

It is owned by the County Highway Agency.