US Bridges

Mn 56 over I 90

Fair

Mower County, Minnesota · At JCT TH 56 · Structure no. 9505

Built
1959
66 years old
Condition
Fair
inspected August 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
201 ft
4 main spans
Daily traffic
2,900
2018 count
Owner
State
State Highway Agency

About this bridge

Mn 56 over I 90 is a steel continuous stringer/multi-beam or girder carrying Mn 56 over I 90 in Mower County, Minnesota. It was built in 1959, so it is 66 years old, older 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 2,900 vehicles a day, roughly 10% of them trucks, projected to reach 3,200 by 2038. The structure is 201 ft (61.3 m) long and 35 ft wide. If it were closed, the detour would be 6.8 mi (11 km).

Location

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CarriesMn 56
CrossesI 90
LocationAt JCT TH 56
RouteState Highway 56
CountyMower County
StateMinnesota
Coordinates43.67148, -92.86923
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
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
Approach roadway alignment8: Equal to present desirable criteria
Operating rating59.4 US tons
Inventory rating35.6 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length201 ft (61.3 m)
Longest span66 ft (20.1 m)
Deck width35 ft (10.7 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,900 (2018)
Projected traffic3,200 by 2038
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed6.8 mi (11 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$976 million
NavigationNot applicable (no waterway)

Frequently asked questions

When was Mn 56 over I 90 built?

It was built in 1959, making it 66 years old in 2025.

What condition is Mn 56 over I 90 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 August 2023.

How much traffic does Mn 56 over I 90 carry?

About 2,900 vehicles per day (2018 count), of which roughly 10% are trucks.

How long is Mn 56 over I 90?

The structure is 201 ft (61.3 m) long with a longest span of 66 ft (20.1 m) and a deck 35 ft wide.

Who owns Mn 56 over I 90?

It is owned by the State Highway Agency.