US Bridges

IRR 104 ST over I029

Fair

Roberts County, South Dakota · 2.0 N Sd 127 Interch · Structure no. 000000055175040

Built
1976
49 years old
Condition
Fair
inspected May 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
293 ft
2 main spans
Daily traffic
68
2023 count
Owner
State
State Highway Agency

About this bridge

IRR 104 ST over I029 is a steel continuous stringer/multi-beam or girder carrying IRR 104 ST over I029 in Roberts County, South Dakota. It was built in 1976, so it is 49 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 68 vehicles a day, roughly 2% of them trucks, projected to reach 68 by 2043. The structure is 293 ft (89.3 m) long and 35 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

CarriesIRR 104 ST
CrossesI029
Location2.0 N Sd 127 Interch
RouteCounty Highway 0
Coordinates45.87803, -96.86478
Functional classRural Local

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.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating63.8 US tons
Inventory rating38.3 US tons

Structure

MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans2 (+2 approach)
Design loadHS 20
Structure length293 ft (89.3 m)
Longest span112 ft (34.1 m)
Deck width35 ft (10.6 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic68 (2023)
Projected traffic68 by 2043
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed3.7 mi (6 km)
TollOn a free road
National Highway SystemNo

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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was IRR 104 ST over I029 built?

It was built in 1976, making it 49 years old in 2025.

What condition is IRR 104 ST over I029 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 May 2023.

How much traffic does IRR 104 ST over I029 carry?

About 68 vehicles per day (2023 count), of which roughly 2% are trucks.

How long is IRR 104 ST over I029?

The structure is 293 ft (89.3 m) long with a longest span of 112 ft (34.1 m) and a deck 35 ft wide.

Who owns IRR 104 ST over I029?

It is owned by the State Highway Agency.