US Bridges

Sth 104 over Allen Creek

Fair

Rock County, Wisconsin · 4.8M N JCT Cth C · Structure no. B53016000000000

Built
1990
35 years old
Condition
Fair
inspected October 2024
Type
Slab
Concrete
Length
39 ft
1 main span
Daily traffic
4,100
2022 count
Owner
State
State Highway Agency

About this bridge

Sth 104 over Allen Creek is a concrete slab carrying Sth 104 over Allen Creek in Rock County, Wisconsin. It was built in 1990, so it is 35 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 4,100 vehicles a day, roughly 8% of them trucks, projected to reach 5,000 by 2043. The structure is 39 ft (11.8 m) long and 34 ft wide. If it were closed, the detour would be 5.6 mi (9 km).

Location

Open in Google Maps
CarriesSth 104
CrossesAllen Creek
Location4.8M N JCT Cth C
RouteState Highway 104
CountyRock County
StateWisconsin
Coordinates42.84003, -89.36912
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.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionOctober 2024
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating71.7 US tons
Inventory rating42.9 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length39 ft (11.8 m)
Longest span37 ft (11.3 m)
Deck width34 ft (10.4 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,100 (2022)
Projected traffic5,000 by 2043
Trucks8%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5.6 mi (9 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—
NavigationNo navigation control on waterway

Frequently asked questions

When was Sth 104 over Allen Creek built?

It was built in 1990, making it 35 years old in 2025.

What condition is Sth 104 over Allen Creek 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 October 2024.

How much traffic does Sth 104 over Allen Creek carry?

About 4,100 vehicles per day (2022 count), of which roughly 8% are trucks.

How long is Sth 104 over Allen Creek?

The structure is 39 ft (11.8 m) long with a longest span of 37 ft (11.3 m) and a deck 34 ft wide.

Who owns Sth 104 over Allen Creek?

It is owned by the State Highway Agency.