US Bridges

County Road 261 over Rock Br

PoorPosted for load

Carroll County, Missouri · S 27 T 55 N R 23 W · Structure no. 15394

Built
1940
85 years old
Condition
Poor
inspected March 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
42 ft
2 main spans
Daily traffic
5
2024 count
Owner
County
County Highway Agency

About this bridge

County Road 261 over Rock Br is a steel stringer/multi-beam or girder carrying County Road 261 over Rock Br in Carroll County, Missouri. It was built in 1940, so it is 85 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 4 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 5 vehicles a day, roughly 10% of them trucks, projected to reach 6 by 2044. The structure is 42 ft (12.8 m) long and 16 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

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CarriesCounty Road 261
CrossesRock Br
LocationS 27 T 55 N R 23 W
RouteCounty Highway 93
CountyCarroll County
StateMissouri
Coordinates39.55497, -93.45849
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
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionMarch 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation2: Basically intolerable, requiring high priority of replacement
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating17.9 US tons
Inventory rating10.9 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans2
Design loadOther
Structure length42 ft (12.8 m)
Longest span23 ft (7 m)
Deck width16 ft (4.9 m)
Roadway width16 ft (4.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic5 (2024)
Projected traffic6 by 2044
Trucks10%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$366,000 (2025 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was County Road 261 over Rock Br built?

It was built in 1940, making it 85 years old in 2025.

What condition is County Road 261 over Rock Br 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 March 2024.

How much traffic does County Road 261 over Rock Br carry?

About 5 vehicles per day (2024 count), of which roughly 10% are trucks.

How long is County Road 261 over Rock Br?

The structure is 42 ft (12.8 m) long with a longest span of 23 ft (7 m) and a deck 16 ft wide.

Who owns County Road 261 over Rock Br?

It is owned by the County Highway Agency.