US Bridges

US085 N over Polo Ck

Fair

Lawrence County, South Dakota · 1 S I 90 Interch · Structure no. 000000041162096

Built
1971
54 years old
Condition
Fair
inspected August 2023
Type
Slab
Concrete Continuous
Length
93 ft
3 main spans
Daily traffic
3,477
2024 count
Owner
State
State Highway Agency

About this bridge

US085 N over Polo Ck is a concrete continuous slab carrying US085 N over Polo Ck in Lawrence County, South Dakota. It was built in 1971, so it is 54 years old, older than the South Dakota average of 48.9 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 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 3,477 vehicles a day, roughly 13% of them trucks, projected to reach 5,038 by 2044. The structure is 93 ft (28.4 m) long and 41 ft wide. If it were closed, the detour would be 0.6 mi (1 km).

CarriesUS085 N
CrossesPolo Ck
Location1 S I 90 Interch
RouteU.S. Route 85
Coordinates44.46508, -103.72778
Functional classRural Principal Arterial - Other

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.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating75.2 US tons
Inventory rating45.1 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20 + Mod
Structure length93 ft (28.4 m)
Longest span33 ft (10.1 m)
Deck width41 ft (12.4 m)
Roadway width38 ft (11.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,477 (2024)
Projected traffic5,038 by 2044
Trucks13%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed0.6 mi (1 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 US085 N over Polo Ck built?

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

What condition is US085 N over Polo Ck 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 August 2023.

How much traffic does US085 N over Polo Ck carry?

About 3,477 vehicles per day (2024 count), of which roughly 13% are trucks.

How long is US085 N over Polo Ck?

The structure is 93 ft (28.4 m) long with a longest span of 33 ft (10.1 m) and a deck 41 ft wide.

Who owns US085 N over Polo Ck?

It is owned by the State Highway Agency.