US Bridges

IRR US018 over Black Tail Ck

Fair

County 102, South Dakota · 1.8 E Fall River CO Line · Structure no. 000000057026360

Built
1953
72 years old
Condition
Fair
inspected September 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
133 ft
3 main spans
Daily traffic
1,294
2024 count
Owner
State
State Highway Agency

About this bridge

IRR US018 over Black Tail Ck is a steel stringer/multi-beam or girder carrying IRR US018 over Black Tail Ck in County 102, South Dakota. It was built in 1953, so it is 72 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 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 1,294 vehicles a day, roughly 7% of them trucks, projected to reach 1,722 by 2044. The structure is 133 ft (40.4 m) long and 32 ft wide. If it were closed, the detour would be 39.8 mi (64 km).

CarriesIRR US018
CrossesBlack Tail Ck
Location1.8 E Fall River CO Line
RouteU.S. Route 18
Coordinates43.18835, -102.96424
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
Deck7 GoodSome minor problems.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionSeptember 2023
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 rating57.9 US tons
Inventory rating34.6 US tons

Structure

MaterialSteel
DeckConcrete, cast-in-place
Main spans3
Design loadH 20
Structure length133 ft (40.4 m)
Longest span43 ft (13 m)
Deck width32 ft (9.8 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,294 (2024)
Projected traffic1,722 by 2044
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed39.8 mi (64 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 IRR US018 over Black Tail Ck built?

It was built in 1953, making it 72 years old in 2025.

What condition is IRR US018 over Black Tail 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 September 2023.

How much traffic does IRR US018 over Black Tail Ck carry?

About 1,294 vehicles per day (2024 count), of which roughly 7% are trucks.

How long is IRR US018 over Black Tail Ck?

The structure is 133 ft (40.4 m) long with a longest span of 43 ft (13 m) and a deck 32 ft wide.

Who owns IRR US018 over Black Tail Ck?

It is owned by the State Highway Agency.