US Bridges

Cth I over Mukwonago River

Poor

Waukesha County, Wisconsin · 0.1M S JCT Cth Lo · Structure no. B67020200000000

Built
1981
44 years old
Condition
Poor
inspected October 2024
Type
Slab
Concrete
Length
42 ft
1 main span
Daily traffic
1,200
2022 count
Owner
County
County Highway Agency

About this bridge

Cth I over Mukwonago River is a concrete slab carrying Cth I over Mukwonago River in Waukesha County, Wisconsin. It was built in 1981, so it is 44 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 1,200 vehicles a day, projected to reach 1,440 by 2043. The structure is 42 ft (12.8 m) long and 30 ft wide. If it were closed, the detour would be 5.6 mi (9 km).

Location

Open in Google Maps
CarriesCth I
CrossesMukwonago River
Location0.1M S JCT Cth Lo
RouteCounty Highway 0I
CountyWaukesha County
StateWisconsin
Coordinates42.86081, -88.36527
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
Deck4 PoorAdvanced section loss, deterioration, spalling or scour.
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionOctober 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 rating68.5 US tons
Inventory rating39.2 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length42 ft (12.8 m)
Longest span40 ft (12.2 m)
Deck width30 ft (9.1 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,200 (2022)
Projected traffic1,440 by 2043
Trucks0%
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

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$276,000 (2024 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Cth I over Mukwonago River built?

It was built in 1981, making it 44 years old in 2025.

What condition is Cth I over Mukwonago 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 October 2024.

How much traffic does Cth I over Mukwonago River carry?

About 1,200 vehicles per day (2022 count).

How long is Cth I over Mukwonago River?

The structure is 42 ft (12.8 m) long with a longest span of 40 ft (12.2 m) and a deck 30 ft wide.

Who owns Cth I over Mukwonago River?

It is owned by the County Highway Agency.