US Bridges

I090 EB Off Ramp over Spearfish Ck

Fair

Lawrence County, South Dakota · 0.3 W US 85 Interch · Structure no. 000000041092059

Built
1971
54 years old
Condition
Fair
inspected January 2025
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
226 ft
3 main spans
Daily traffic
1,291
2023 count
Owner
State
State Highway Agency

About this bridge

I090 EB Off Ramp over Spearfish Ck is a steel continuous stringer/multi-beam or girder carrying I090 EB Off Ramp over Spearfish 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 1,291 vehicles a day, roughly 10% of them trucks, projected to reach 2,027 by 2043. The structure is 226 ft (68.9 m) long and 27 ft wide. If it were closed, the detour would be 0.6 mi (1 km).

Location

Open in Google Maps
CarriesI090 EB Off Ramp
CrossesSpearfish Ck
Location0.3 W US 85 Interch
RouteInterstate 90
CountyLawrence County
StateSouth Dakota
Coordinates44.51965, -103.86683
Functional classUrban Principal Arterial - Interstate

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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJanuary 2025
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 adequacy9: Superior to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating71.8 US tons
Inventory rating43 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length226 ft (68.9 m)
Longest span85 ft (25.9 m)
Deck width27 ft (8.1 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,291 (2023)
Projected traffic2,027 by 2043
Trucks10%
Lanes on structure1
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 I090 EB Off Ramp over Spearfish Ck built?

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

What condition is I090 EB Off Ramp over Spearfish 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 January 2025.

How much traffic does I090 EB Off Ramp over Spearfish Ck carry?

About 1,291 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is I090 EB Off Ramp over Spearfish Ck?

The structure is 226 ft (68.9 m) long with a longest span of 85 ft (25.9 m) and a deck 27 ft wide.

Who owns I090 EB Off Ramp over Spearfish Ck?

It is owned by the State Highway Agency.