US Bridges

Cth D over Namekagon Lake

Poor

Bayfield County, Wisconsin · 4.0M N JCT Cth M · Structure no. B04001800000000

Built
1971
54 years old
Condition
Poor
inspected August 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete Continuous
Length
184 ft
3 main spans
Daily traffic
575
2022 count
Owner
County
County Highway Agency

About this bridge

Cth D over Namekagon Lake is a prestressed concrete continuous stringer/multi-beam or girder carrying Cth D over Namekagon Lake in Bayfield County, Wisconsin. It was built in 1971, so it is 54 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 575 vehicles a day, projected to reach 610 by 2043. The structure is 184 ft (56.1 m) long and 36 ft wide. If it were closed, the detour would be 12.4 mi (20 km).

Location

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CarriesCth D
CrossesNamekagon Lake
Location4.0M N JCT Cth M
RouteCounty Highway 0D
CountyBayfield County
StateWisconsin
Coordinates46.23119, -91.08653
Functional classRural Major 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.
Superstructure7 GoodSome minor problems.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionAugust 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 geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating46.8 US tons
Inventory rating19.6 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadH 20
Structure length184 ft (56.1 m)
Longest span61 ft (18.7 m)
Deck width36 ft (10.9 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic575 (2022)
Projected traffic610 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$859,000 (2024 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Cth D over Namekagon Lake built?

It was built in 1971, making it 54 years old in 2025.

What condition is Cth D over Namekagon Lake 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 August 2024.

How much traffic does Cth D over Namekagon Lake carry?

About 575 vehicles per day (2022 count).

How long is Cth D over Namekagon Lake?

The structure is 184 ft (56.1 m) long with a longest span of 61 ft (18.7 m) and a deck 36 ft wide.

Who owns Cth D over Namekagon Lake?

It is owned by the County Highway Agency.