US Bridges

Cth I over Clam River

Poor

Polk County, Wisconsin · 1.8M W JCT Cth O · Structure no. B48000100000000

Built
1948
77 years old
Condition
Poor
inspected April 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
68 ft
1 main span
Daily traffic
490
2024 count
Owner
County
County Highway Agency

About this bridge

Cth I over Clam River is a steel stringer/multi-beam or girder carrying Cth I over Clam River in Polk County, Wisconsin. It was built in 1948, so it is 77 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 490 vehicles a day, projected to reach 942 by 2043. The structure is 68 ft (20.7 m) long and 25 ft wide. If it were closed, the detour would be 12.4 mi (20 km).

Location

Open in Google Maps
CarriesCth I
CrossesClam River
Location1.8M W JCT Cth O
RouteCounty Highway 0I
CountyPolk County
StateWisconsin
Coordinates45.68738, -92.29553
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionApril 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 geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating37.8 US tons
Inventory rating21.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadH 15
Structure length68 ft (20.7 m)
Longest span66 ft (20.1 m)
Deck width25 ft (7.5 m)
Roadway width22 ft (6.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic490 (2024)
Projected traffic942 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed12.4 mi (20 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$358,000 (2024 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Cth I over Clam River built?

It was built in 1948, making it 77 years old in 2025.

What condition is Cth I over Clam River 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 April 2024.

How much traffic does Cth I over Clam River carry?

About 490 vehicles per day (2024 count).

How long is Cth I over Clam River?

The structure is 68 ft (20.7 m) long with a longest span of 66 ft (20.1 m) and a deck 25 ft wide.

Who owns Cth I over Clam River?

It is owned by the County Highway Agency.