US Bridges

Mo 221 S over W Br of Knob CR

Fair

Iron County, Missouri · S 19 T 34 N R 4 E · Structure no. 11872

Built
2000
25 years old
Condition
Fair
inspected October 2023
Type
Culvert
Concrete Continuous
Length
51 ft
3 main spans
Daily traffic
2,220
2024 count
Owner
State
State Highway Agency

About this bridge

Mo 221 S over W Br of Knob CR is a concrete continuous culvert carrying Mo 221 S over W Br of Knob CR in Iron County, Missouri. It was built in 2000, so it is 25 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 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 2,220 vehicles a day, roughly 5% of them trucks, projected to reach 3,330 by 2044. The structure is 51 ft (15.5 m) long and 67 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesMo 221 S
CrossesW Br of Knob CR
LocationS 19 T 34 N R 4 E
RouteState Highway 221
CountyIron County
StateMissouri
Coordinates37.61736, -90.64073
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.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating110.1 US tons
Inventory rating84.3 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans3
Design loadHS 20
Structure length51 ft (15.5 m)
Longest span16 ft (4.8 m)
Deck width67 ft (20.3 m)
Roadway width63 ft (19.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,220 (2024)
Projected traffic3,330 by 2044
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 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 221 S over W Br of Knob CR built?

It was built in 2000, making it 25 years old in 2025.

What condition is Mo 221 S over W Br of Knob 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 October 2023.

How much traffic does Mo 221 S over W Br of Knob CR carry?

About 2,220 vehicles per day (2024 count), of which roughly 5% are trucks.

How long is Mo 221 S over W Br of Knob CR?

The structure is 51 ft (15.5 m) long with a longest span of 16 ft (4.8 m) and a deck 67 ft wide.

Who owns Mo 221 S over W Br of Knob CR?

It is owned by the State Highway Agency.