US Bridges

Mo 21 S over Tanyard Br

Fair

Jefferson County, Missouri · S 3 T 39 N R 4 E · Structure no. 6033

Built
1946
79 years old
Condition
Fair
inspected December 2024
Type
Culvert
Concrete Continuous
Length
21 ft
2 main spans
Daily traffic
8,707
2024 count
Owner
State
State Highway Agency

About this bridge

Mo 21 S over Tanyard Br is a concrete continuous culvert carrying Mo 21 S over Tanyard Br in Jefferson County, Missouri. It was built in 1946, so it is 79 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 8,707 vehicles a day, roughly 9% of them trucks, projected to reach 14,802 by 2044. The structure is 21 ft (6.4 m) long. If it were closed, the detour would be 34.8 mi (56 km).

Location

Open in Google Maps
CarriesMo 21 S
CrossesTanyard Br
LocationS 3 T 39 N R 4 E
RouteState Highway 21
CountyJefferson County
StateMissouri
Coordinates38.13408, -90.57562
Functional classUrban Other Principal 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 protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionDecember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating70.4 US tons
Inventory rating42.7 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans2
Design loadH 15
Structure length21 ft (6.4 m)
Longest span10 ft (3 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic8,707 (2024)
Projected traffic14,802 by 2044
Trucks9%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed34.8 mi (56 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 Tanyard Br built?

It was built in 1946, making it 79 years old in 2025.

What condition is Mo 21 S over Tanyard Br 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 2024.

How much traffic does Mo 21 S over Tanyard Br carry?

About 8,707 vehicles per day (2024 count), of which roughly 9% are trucks.

How long is Mo 21 S over Tanyard Br?

The structure is 21 ft (6.4 m) long with a longest span of 10 ft (3 m).

Who owns Mo 21 S over Tanyard Br?

It is owned by the State Highway Agency.