US Bridges

475 Ave over I029

Fair

Union County, South Dakota · 6.2 SE Sd 50 Interch · Structure no. 000000064050250

Built
1960
65 years old
Condition
Fair
inspected January 2025
Type
Slab
Concrete Continuous
Length
254 ft
4 main spans
Daily traffic
30
2023 count
Owner
State
State Highway Agency

About this bridge

475 Ave over I029 is a concrete continuous slab carrying 475 Ave over I029 in Union County, South Dakota. It was built in 1960, so it is 65 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 30 vehicles a day, roughly 2% of them trucks, projected to reach 30 by 2043. The structure is 254 ft (77.4 m) long and 28 ft wide.

Location

Open in Google Maps
Carries475 Ave
CrossesI029
Location6.2 SE Sd 50 Interch
RouteCounty Highway 0
CountyUnion County
StateSouth Dakota
Coordinates42.72138, -96.70731
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 inspectionJanuary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Approach roadway alignment5: Somewhat better than minimum adequacy to tolerate being left in place as is
Operating rating53.5 US tons
Inventory rating32 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadH 20
Structure length254 ft (77.4 m)
Longest span65 ft (19.8 m)
Deck width28 ft (8.5 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic30 (2023)
Projected traffic30 by 2043
Trucks2%
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 475 Ave over I029 built?

It was built in 1960, making it 65 years old in 2025.

What condition is 475 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 January 2025.

How much traffic does 475 Ave over I029 carry?

About 30 vehicles per day (2023 count), of which roughly 2% are trucks.

How long is 475 Ave over I029?

The structure is 254 ft (77.4 m) long with a longest span of 65 ft (19.8 m) and a deck 28 ft wide.

Who owns 475 Ave over I029?

It is owned by the State Highway Agency.