US Bridges

Mo 21 S over N Prong CR

Fair

Carter County, Missouri · S 15 T 26 N R 2 E · Structure no. 5434

Built
1931
94 years old
Condition
Fair
inspected December 2023
Type
Culvert
Concrete Continuous
Length
28 ft
2 main spans
Daily traffic
2,035
2024 count
Owner
State
State Highway Agency

About this bridge

Mo 21 S over N Prong CR is a concrete continuous culvert carrying Mo 21 S over N Prong CR in Carter County, Missouri. It was built in 1931, so it is 94 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 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 2,035 vehicles a day, roughly 18% of them trucks, projected to reach 3,053 by 2044. The structure is 28 ft (8.4 m) long and 35 ft wide. If it were closed, the detour would be 19.9 mi (32 km).

Location

Open in Google Maps
CarriesMo 21 S
CrossesN Prong CR
LocationS 15 T 26 N R 2 E
RouteState Highway 21
CountyCarter County
StateMissouri
Coordinates36.9009, -90.83911
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
Channel and channel protection7 GoodSome minor problems.
Culvert5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionDecember 2023
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 geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating80.4 US tons
Inventory rating48.6 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans2
Design loadH 15
Structure length28 ft (8.4 m)
Longest span10 ft (3 m)
Deck width35 ft (10.7 m)
Roadway width33 ft (10.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,035 (2024)
Projected traffic3,053 by 2044
Trucks18%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed19.9 mi (32 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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 Mo 21 S over N Prong CR built?

It was built in 1931, making it 94 years old in 2025.

What condition is Mo 21 S over N Prong 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 December 2023.

How much traffic does Mo 21 S over N Prong CR carry?

About 2,035 vehicles per day (2024 count), of which roughly 18% are trucks.

How long is Mo 21 S over N Prong CR?

The structure is 28 ft (8.4 m) long with a longest span of 10 ft (3 m) and a deck 35 ft wide.

Who owns Mo 21 S over N Prong CR?

It is owned by the State Highway Agency.