US Bridges

408th Ave. over Redstone Ck

Fair

Sanborn County, South Dakota · 3E 2.4N Forestburg · Structure no. 000000056140096

Built
1965
60 years old
Condition
Fair
inspected July 2023
Type
Channel Beam
Concrete
Length
52 ft
2 main spans
Daily traffic
120
2022 count
Owner
County
County Highway Agency

About this bridge

408th Ave. over Redstone Ck is a concrete channel beam carrying 408th Ave. over Redstone Ck in Sanborn County, South Dakota. It was built in 1965, so it is 60 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 120 vehicles a day, roughly 3% of them trucks, projected to reach 120 by 2032. The structure is 52 ft (15.8 m) long and 32 ft wide. If it were closed, the detour would be 9.9 mi (16 km).

Location

Open in Google Maps
Carries408th Ave.
CrossesRedstone Ck
Location3E 2.4N Forestburg
RouteCounty Highway 0
CountySanborn County
StateSouth Dakota
Coordinates44.06006, -98.0514
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
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.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating36 US tons
Inventory rating27 US tons

Structure

Structure typeChannel Beam
MaterialConcrete
DeckConcrete, precast panels
Main spans2
Design loadUnknown
Structure length52 ft (15.8 m)
Longest span25 ft (7.6 m)
Deck width32 ft (9.8 m)
Roadway width31 ft (9.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic120 (2022)
Projected traffic120 by 2032
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed9.9 mi (16 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$6,000
NavigationNo navigation control on waterway

Frequently asked questions

When was 408th Ave. over Redstone Ck built?

It was built in 1965, making it 60 years old in 2025.

What condition is 408th Ave. over Redstone 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 July 2023.

How much traffic does 408th Ave. over Redstone Ck carry?

About 120 vehicles per day (2022 count), of which roughly 3% are trucks.

How long is 408th Ave. over Redstone Ck?

The structure is 52 ft (15.8 m) long with a longest span of 25 ft (7.6 m) and a deck 32 ft wide.

Who owns 408th Ave. over Redstone Ck?

It is owned by the County Highway Agency.