US Bridges

Csah 12 over Zumbro River

Fair

Olmsted County, Minnesota · 2.6 MI W of JCT TH 63 · Structure no. 55520

Built
1975
50 years old
Condition
Fair
inspected November 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
496 ft
4 main spans
Daily traffic
2,050
2018 count
Owner
County
County Highway Agency

About this bridge

Csah 12 over Zumbro River is a steel continuous stringer/multi-beam or girder carrying Csah 12 over Zumbro River in Olmsted County, Minnesota. It was built in 1975, so it is 50 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 2,050 vehicles a day, projected to reach 1,948 by 2038. The structure is 496 ft (151.2 m) long and 52 ft wide. If it were closed, the detour would be 9.9 mi (16 km).

Location

Open in Google Maps
CarriesCsah 12
CrossesZumbro River
Location2.6 MI W of JCT TH 63
RouteCounty Highway 12
CountyOlmsted County
StateMinnesota
Coordinates44.17008, -92.46882
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
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
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 inspectionNovember 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 geometry7: Better than present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating65.1 US tons
Inventory rating39.1 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length496 ft (151.2 m)
Longest span135 ft (41.1 m)
Deck width52 ft (15.8 m)
Roadway width44 ft (13.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,050 (2018)
Projected traffic1,948 by 2038
Trucks—
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed9.9 mi (16 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty 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 Csah 12 over Zumbro River built?

It was built in 1975, making it 50 years old in 2025.

What condition is Csah 12 over Zumbro 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 November 2023.

How much traffic does Csah 12 over Zumbro River carry?

About 2,050 vehicles per day (2018 count).

How long is Csah 12 over Zumbro River?

The structure is 496 ft (151.2 m) long with a longest span of 135 ft (41.1 m) and a deck 52 ft wide.

Who owns Csah 12 over Zumbro River?

It is owned by the County Highway Agency.