US Bridges

Cth N over Little Door Creek

Poor

Dane County, Wisconsin · 0.7M N JCT Ush 12 · Structure no. B13004200000000

Built
1954
71 years old
Condition
Poor
inspected October 2024
Type
Slab
Concrete
Length
23 ft
1 main span
Daily traffic
5,800
2022 count
Owner
County
County Highway Agency

About this bridge

Cth N over Little Door Creek is a concrete slab carrying Cth N over Little Door Creek in Dane County, Wisconsin. It was built in 1954, so it is 71 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 5,800 vehicles a day, projected to reach 6,960 by 2042. The structure is 23 ft (7 m) long and 29 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesCth N
CrossesLittle Door Creek
Location0.7M N JCT Ush 12
RouteCounty Highway 0N
CountyDane County
StateWisconsin
Coordinates43.04039, -89.19978
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
Deck4 PoorAdvanced section loss, deterioration, spalling or scour.
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
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 geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating48.6 US tons
Inventory rating28.5 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadH 15
Structure length23 ft (7 m)
Longest span22 ft (6.6 m)
Deck width29 ft (8.7 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic5,800 (2022)
Projected traffic6,960 by 2042
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 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$215,000 (2024 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Cth N over Little Door Creek built?

It was built in 1954, making it 71 years old in 2025.

What condition is Cth N over Little Door Creek 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 N over Little Door Creek carry?

About 5,800 vehicles per day (2022 count).

How long is Cth N over Little Door Creek?

The structure is 23 ft (7 m) long with a longest span of 22 ft (6.6 m) and a deck 29 ft wide.

Who owns Cth N over Little Door Creek?

It is owned by the County Highway Agency.