US Bridges

Cth X over Big Slough

Poor

Columbia County, Wisconsin · 2.6M S JCT Cth Aa · Structure no. P11005400000000

Built
1958
67 years old
Condition
Poor
inspected September 2024
Type
Slab
Wood or Timber
Length
80 ft
4 main spans
Daily traffic
451
2022 count
Owner
County
County Highway Agency

About this bridge

Cth X over Big Slough is a wood or timber slab carrying Cth X over Big Slough in Columbia County, Wisconsin. It was built in 1958, so it is 67 years old, older than the Wisconsin average of 40.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 451 vehicles a day, projected to reach 496 by 2043. The structure is 80 ft (24.4 m) long and 28 ft wide. If it were closed, the detour would be 23.6 mi (38 km).

Location

Open in Google Maps
CarriesCth X
CrossesBig Slough
Location2.6M S JCT Cth Aa
RouteCounty Highway 0X
CountyColumbia County
StateWisconsin
Coordinates43.62911, -89.55863
Functional classRural Minor Collector

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionSeptember 2024
Inspection intervalevery 12 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating70.2 US tons
Inventory rating50 US tons

Structure

Structure typeSlab
MaterialWood or Timber
DeckWood or timber
Main spans4
Design loadH 15
Structure length80 ft (24.4 m)
Longest span20 ft (6.1 m)
Deck width28 ft (8.4 m)
Roadway width26 ft (8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic451 (2022)
Projected traffic496 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed23.6 mi (38 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$410,000 (2024 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Cth X over Big Slough built?

It was built in 1958, making it 67 years old in 2025.

What condition is Cth X over Big Slough in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in September 2024.

How much traffic does Cth X over Big Slough carry?

About 451 vehicles per day (2022 count).

How long is Cth X over Big Slough?

The structure is 80 ft (24.4 m) long with a longest span of 20 ft (6.1 m) and a deck 28 ft wide.

Who owns Cth X over Big Slough?

It is owned by the County Highway Agency.