US Bridges

484 Ave over I029

Fair

Union County, South Dakota · 3.4 NW N Scity Interch · Structure no. 000000064140355

Built
1961
64 years old
Condition
Fair
inspected October 2023
Type
Box Beam or Girders - Multiple
Concrete Continuous
Length
365 ft
4 main spans
Daily traffic
240
2023 count
Owner
State
State Highway Agency

About this bridge

484 Ave over I029 is a concrete continuous box beam or girders - multiple carrying 484 Ave over I029 in Union County, South Dakota. It was built in 1961, so it is 64 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 240 vehicles a day, roughly 5% of them trucks, projected to reach 240 by 2043. The structure is 365 ft (111.3 m) long and 34 ft wide.

Carries484 Ave
CrossesI029
Location3.4 NW N Scity Interch
RouteCounty Highway 0
Coordinates42.5685, -96.52659
Functional classRural Major Collector

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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating43 US tons
Inventory rating25.4 US tons

Structure

MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length365 ft (111.3 m)
Longest span100 ft (30.5 m)
Deck width34 ft (10.5 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic240 (2023)
Projected traffic240 by 2043
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed—
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 484 Ave over I029 built?

It was built in 1961, making it 64 years old in 2025.

What condition is 484 Ave 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 October 2023.

How much traffic does 484 Ave over I029 carry?

About 240 vehicles per day (2023 count), of which roughly 5% are trucks.

How long is 484 Ave over I029?

The structure is 365 ft (111.3 m) long with a longest span of 100 ft (30.5 m) and a deck 34 ft wide.

Who owns 484 Ave over I029?

It is owned by the State Highway Agency.