US Bridges

County RD 457 over Unknown Branch

Fair

Callaway County, Missouri · S 27 T 46 N R 8 W · Structure no. 22061

Built
1986
39 years old
Condition
Fair
inspected October 2024
Type
Girder and Floorbeam System
Steel
Length
60 ft
1 main span
Daily traffic
40
2023 count
Owner
County
County Highway Agency

About this bridge

County RD 457 over Unknown Branch is a steel girder and floorbeam system carrying County RD 457 over Unknown Branch in Callaway County, Missouri. It was built in 1986, so it is 39 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.

It carries about 40 vehicles a day, roughly 5% of them trucks, projected to reach 60 by 2043. The structure is 60 ft (18.3 m) long and 16 ft wide. If it were closed, the detour would be 0.6 mi (1 km).

Location

Open in Google Maps
CarriesCounty RD 457
CrossesUnknown Branch
LocationS 27 T 46 N R 8 W
RouteCounty Highway 338
CountyCallaway County
StateMissouri
Coordinates38.72717, -91.80428
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry7: Better than present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating42.7 US tons
Inventory rating18.8 US tons

Structure

Structure typeGirder and Floorbeam System
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadOther
Structure length60 ft (18.3 m)
Longest span60 ft (18.3 m)
Deck width16 ft (4.9 m)
Roadway width15 ft (4.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic40 (2023)
Projected traffic60 by 2043
Trucks5%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed0.6 mi (1 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 457 over Unknown Branch built?

It was built in 1986, making it 39 years old in 2025.

What condition is County RD 457 over Unknown Branch 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 October 2024.

How much traffic does County RD 457 over Unknown Branch carry?

About 40 vehicles per day (2023 count), of which roughly 5% are trucks.

How long is County RD 457 over Unknown Branch?

The structure is 60 ft (18.3 m) long with a longest span of 60 ft (18.3 m) and a deck 16 ft wide.

Who owns County RD 457 over Unknown Branch?

It is owned by the County Highway Agency.