US Bridges

483 Avenue over Cobb Ck

Fair

Deuel County, South Dakota · 4.1 N Astoria · Structure no. 000000020170249

Built
1956
69 years old
Condition
Fair
inspected June 2023
Type
Slab
Concrete Continuous
Length
106 ft
5 main spans
Daily traffic
157
2022 count
Owner
County
County Highway Agency

About this bridge

483 Avenue over Cobb Ck is a concrete continuous slab carrying 483 Avenue over Cobb Ck in Deuel County, South Dakota. It was built in 1956, so it is 69 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 157 vehicles a day, roughly 3% of them trucks, projected to reach 157 by 2032. The structure is 106 ft (32.3 m) long and 28 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

Carries483 Avenue
CrossesCobb Ck
Location4.1 N Astoria
RouteCounty Highway 0
Coordinates44.61673, -96.54126
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating37 US tons
Inventory rating22 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans5
Design loadH 15
Structure length106 ft (32.3 m)
Longest span23 ft (6.9 m)
Deck width28 ft (8.6 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic157 (2022)
Projected traffic157 by 2032
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.1 mi (13 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$50,000
NavigationNo navigation control on waterway

Frequently asked questions

When was 483 Avenue over Cobb Ck built?

It was built in 1956, making it 69 years old in 2025.

What condition is 483 Avenue over Cobb 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 June 2023.

How much traffic does 483 Avenue over Cobb Ck carry?

About 157 vehicles per day (2022 count), of which roughly 3% are trucks.

How long is 483 Avenue over Cobb Ck?

The structure is 106 ft (32.3 m) long with a longest span of 23 ft (6.9 m) and a deck 28 ft wide.

Who owns 483 Avenue over Cobb Ck?

It is owned by the County Highway Agency.