US Bridges

Sth 81-PORTLAND Av over Rock River

Fair

Rock County, Wisconsin · 0.1M E JCT Sth 213 to N · Structure no. B53017200000000

Built
1996
29 years old
Condition
Fair
inspected September 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete Continuous
Length
546 ft
6 main spans
Daily traffic
18,200
2022 count
Owner
State
State Highway Agency

About this bridge

Sth 81-PORTLAND Av over Rock River is a prestressed concrete continuous stringer/multi-beam or girder carrying Sth 81-PORTLAND Av over Rock River in Rock County, Wisconsin. It was built in 1996, so it is 29 years old, younger than the Wisconsin average of 40.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 18,200 vehicles a day, projected to reach 21,840 by 2043. The structure is 546 ft (166.3 m) long and 74 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

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CarriesSth 81-PORTLAND Av
CrossesRock River
Location0.1M E JCT Sth 213 to N
RouteState Highway 81
CountyRock County
StateWisconsin
Coordinates42.50751, -89.03516
Functional classUrban Other Principal Arterial

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being 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 rating79.1 US tons
Inventory rating48.2 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans6
Design loadHS 20
Structure length546 ft (166.3 m)
Longest span90 ft (27.5 m)
Deck width74 ft (22.6 m)
Roadway width58 ft (17.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic18,200 (2022)
Projected traffic21,840 by 2043
Trucks0%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Sth 81-PORTLAND Av over Rock River built?

It was built in 1996, making it 29 years old in 2025.

What condition is Sth 81-PORTLAND Av over Rock River in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in September 2024.

How much traffic does Sth 81-PORTLAND Av over Rock River carry?

About 18,200 vehicles per day (2022 count).

How long is Sth 81-PORTLAND Av over Rock River?

The structure is 546 ft (166.3 m) long with a longest span of 90 ft (27.5 m) and a deck 74 ft wide.

Who owns Sth 81-PORTLAND Av over Rock River?

It is owned by the State Highway Agency.