US Bridges

IRR 129 ST over I029

Fair

Roberts County, South Dakota · 2 S Peever Interch · Structure no. 000000055115290

Built
1978
47 years old
Condition
Fair
inspected May 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
292 ft
2 main spans
Daily traffic
254
2023 count
Owner
State
State Highway Agency

About this bridge

IRR 129 ST over I029 is a steel continuous stringer/multi-beam or girder carrying IRR 129 ST over I029 in Roberts County, South Dakota. It was built in 1978, so it is 47 years old, younger 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 254 vehicles a day, roughly 2% of them trucks, projected to reach 254 by 2043. The structure is 292 ft (89.1 m) long and 35 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesIRR 129 ST
CrossesI029
Location2 S Peever Interch
RouteCounty Highway 0
CountyRoberts County
StateSouth Dakota
Coordinates45.51477, -96.98885
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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry7: Better than present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating58.6 US tons
Inventory rating35.1 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans2 (+2 approach)
Design loadHS 20 + Mod
Structure length292 ft (89.1 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 traffic254 (2023)
Projected traffic254 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 129 ST over I029 built?

It was built in 1978, making it 47 years old in 2025.

What condition is IRR 129 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 129 ST over I029 carry?

About 254 vehicles per day (2023 count), of which roughly 2% are trucks.

How long is IRR 129 ST over I029?

The structure is 292 ft (89.1 m) long with a longest span of 112 ft (34.1 m) and a deck 35 ft wide.

Who owns IRR 129 ST over I029?

It is owned by the State Highway Agency.