US Bridges

Mn 22 over Big Cobb River

Fair

Blue Earth County, Minnesota · 4.8 MI N of Mapleton · Structure no. 07051

Built
2017
8 years old
Condition
Fair
inspected May 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
283 ft
3 main spans
Daily traffic
5,500
2019 count
Owner
State
State Highway Agency

About this bridge

Mn 22 over Big Cobb River is a prestressed concrete stringer/multi-beam or girder carrying Mn 22 over Big Cobb River in Blue Earth County, Minnesota. It was built in 2017, so it is 8 years old, younger than the Minnesota average of 38.5 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 5,500 vehicles a day, roughly 10% of them trucks, projected to reach 5,300 by 2039. The structure is 283 ft (86.2 m) long and 43 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

Open in Google Maps
CarriesMn 22
CrossesBig Cobb River
Location4.8 MI N of Mapleton
RouteState Highway 22
CountyBlue Earth County
StateMinnesota
Coordinates44.00034, -93.95841
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
Deck8 Very GoodNo problems noted.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMay 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating69.7 US tons
Inventory rating35.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHL 93
Structure length283 ft (86.2 m)
Longest span133 ft (40.5 m)
Deck width43 ft (13.2 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic5,500 (2019)
Projected traffic5,300 by 2039
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Mn 22 over Big Cobb River built?

It was built in 2017, making it 8 years old in 2025.

What condition is Mn 22 over Big Cobb River 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 May 2024.

How much traffic does Mn 22 over Big Cobb River carry?

About 5,500 vehicles per day (2019 count), of which roughly 10% are trucks.

How long is Mn 22 over Big Cobb River?

The structure is 283 ft (86.2 m) long with a longest span of 133 ft (40.5 m) and a deck 43 ft wide.

Who owns Mn 22 over Big Cobb River?

It is owned by the State Highway Agency.