US Bridges

M 11 over Spring Brook

Fair

Rock County, Minnesota · 0.2 MI E of JCT Csah 25 · Structure no. L4646

Built
1911
114 years old
Condition
Fair
inspected November 2024
Type
Arch - Deck
Concrete
Length
38 ft
1 main span
Daily traffic
56
1990 count
Owner
City
City or Municipal Highway Agency

About this bridge

M 11 over Spring Brook is a concrete arch - deck carrying M 11 over Spring Brook in Rock County, Minnesota. It was built in 1911, so it is 114 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 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 56 vehicles a day, projected to reach 56 by 2029. The structure is 38 ft (11.6 m) long and 19 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesM 11
CrossesSpring Brook
Location0.2 MI E of JCT Csah 25
RouteCity Street 11
CountyRock County
StateMinnesota
Coordinates43.61524, -96.35982
Functional classRural Local

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionNovember 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 geometry8: Equal to present desirable criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating32.4 US tons
Inventory rating21.6 US tons

Structure

Structure typeArch - Deck
MaterialConcrete
DeckNot applicable
Main spans1
Design loadUnknown
Structure length38 ft (11.6 m)
Longest span32 ft (9.8 m)
Deck width19 ft (5.7 m)
Roadway width16 ft (4.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic56 (1990)
Projected traffic56 by 2029
Trucks—
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusListed on the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost$120 million
NavigationNo navigation control on waterway

Frequently asked questions

When was M 11 over Spring Brook built?

It was built in 1911, making it 114 years old in 2025.

What condition is M 11 over Spring Brook 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 2024.

How much traffic does M 11 over Spring Brook carry?

About 56 vehicles per day (1990 count).

How long is M 11 over Spring Brook?

The structure is 38 ft (11.6 m) long with a longest span of 32 ft (9.8 m) and a deck 19 ft wide.

Who owns M 11 over Spring Brook?

It is owned by the City or Municipal Highway Agency.