US Bridges

Csah 16 over Big Cobb River

Good

Blue Earth County, Minnesota · 2.6 MI NW of JCT TH 22 · Structure no. 07545

Built
1978
47 years old
Condition
Good
inspected October 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
264 ft
3 main spans
Daily traffic
510
2018 count
Owner
County
County Highway Agency

About this bridge

Csah 16 over Big Cobb River is a prestressed concrete stringer/multi-beam or girder carrying Csah 16 over Big Cobb River in Blue Earth County, Minnesota. It was built in 1978, so it is 47 years old, older than the Minnesota average of 38.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 510 vehicles a day, projected to reach 470 by 2038. The structure is 264 ft (80.6 m) long and 35 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

CarriesCsah 16
CrossesBig Cobb River
Location2.6 MI NW of JCT TH 22
RouteCounty Highway 16
Coordinates44.04725, -94.00053
Functional classRural Major Collector

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating50.2 US tons
Inventory rating30.1 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length264 ft (80.6 m)
Longest span86 ft (26.3 m)
Deck width35 ft (10.8 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic510 (2018)
Projected traffic470 by 2038
Trucks—
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

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 16 over Big Cobb River built?

It was built in 1978, making it 47 years old in 2025.

What condition is Csah 16 over Big Cobb River in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in October 2024.

How much traffic does Csah 16 over Big Cobb River carry?

About 510 vehicles per day (2018 count).

How long is Csah 16 over Big Cobb River?

The structure is 264 ft (80.6 m) long with a longest span of 86 ft (26.3 m) and a deck 35 ft wide.

Who owns Csah 16 over Big Cobb River?

It is owned by the County Highway Agency.