US Bridges

Sth 64 over St. Croix River

Fair

St. Croix County, Wisconsin · 0.1M W. of WI-35 · Structure no. B55022400000000

Built
2017
8 years old
Condition
Fair
inspected August 2023
Type
Segmental Box Girder
Concrete
Length
5,079 ft
14 main spans
Daily traffic
28,000
2021 count
Owner
State
State Highway Agency

About this bridge

Sth 64 over St. Croix River is a concrete segmental box girder carrying Sth 64 over St. Croix River in St. Croix County, Wisconsin. It was built in 2017, so it is 8 years old, younger than the Wisconsin average of 40.3 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 28,000 vehicles a day, roughly 7% of them trucks, projected to reach 33,600 by 2041. The structure is 5,079 ft (1,548.1 m) long and 87 ft wide. If it were closed, the detour would be 15.5 mi (25 km).

Location

Open in Google Maps
CarriesSth 64
CrossesSt. Croix River
Location0.1M W. of WI-35
RouteState Highway 64
CountySt. Croix County
StateWisconsin
Coordinates45.04628, -92.78133
Functional classRural Principal Arterial - Other

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.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating66.8 US tons
Inventory rating43.2 US tons

Structure

Structure typeSegmental Box Girder
MaterialConcrete
DeckConcrete, cast-in-place
Main spans14
Design loadHL 93
Structure length5,079 ft (1,548.1 m)
Longest span600 ft (182.9 m)
Deck width87 ft (26.4 m)
Roadway width80 ft (24.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic28,000 (2021)
Projected traffic33,600 by 2041
Trucks7%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesHighway, waterway and railroad
Detour if closed15.5 mi (25 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$28.9 million (2024 estimate)
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was Sth 64 over St. Croix River built?

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

What condition is Sth 64 over St. Croix 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 August 2023.

How much traffic does Sth 64 over St. Croix River carry?

About 28,000 vehicles per day (2021 count), of which roughly 7% are trucks.

How long is Sth 64 over St. Croix River?

The structure is 5,079 ft (1,548.1 m) long with a longest span of 600 ft (182.9 m) and a deck 87 ft wide.

Who owns Sth 64 over St. Croix River?

It is owned by the State Highway Agency.