SD050 over Nelson Ck

Good

Brule County, South Dakota · 4.6 S I 90 Interch · Structure no. 000000008150166

Built: 1970; 55 years old
Condition: Good; inspected June 2023
Type: Slab; Concrete Continuous
Length: 106 ft; 3 main spans
Daily traffic: 284; 2024 count
Owner: State; State Highway Agency

About this bridge

SD050 over Nelson Ck is a concrete continuous slab carrying SD050 over Nelson Ck in Brule County, South Dakota. It was built in 1970, so it is 55 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 good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 284 vehicles a day, roughly 11% of them trucks, projected to reach 368 by 2044. The structure is 106 ft (32.3 m) long and 43 ft wide. If it were closed, the detour would be 31.7 mi (51 km).

Location

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CarriesSD050

CrossesNelson Ck

Location4.6 S I 90 Interch

RouteState Highway 50

CountyBrule County

StateSouth Dakota

Coordinates43.69312, -99.17169

Functional classRural Minor Arterial

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

Component	Rating	Meaning
Deck	7 Good	Some minor problems.
Superstructure	7 Good	Some minor problems.
Substructure	7 Good	Some minor problems.
Channel and channel protection	8 Very Good	No problems noted.

Last inspectionJune 2023

Inspection intervalevery 48 months

Operating statusOpen, no restriction

ScourCountermeasures installed to correct a previously existing problem

Structural evaluation7: Better than present minimum criteria

Deck geometry9: Superior to present desirable criteria

Waterway adequacy8: Equal to present desirable criteria

Approach roadway alignment8: Equal to present desirable criteria

Operating rating77.1 US tons

Inventory rating46.1 US tons

Structure

Structure typeSlab

MaterialConcrete Continuous

DeckConcrete, cast-in-place

Main spans3

Design loadHS 20

Structure length106 ft (32.3 m)

Longest span38 ft (11.5 m)

Deck width43 ft (13 m)

Roadway width40 ft (12.2 m)

Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic284 (2024)

Projected traffic368 by 2044

Trucks11%

Lanes on structure2

Traffic directionTwo-way traffic

CarriesHighway

CrossesWaterway

Detour if closed31.7 mi (51 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—

NavigationNo navigation control on waterway

Frequently asked questions

When was SD050 over Nelson Ck built?

It was built in 1970, making it 55 years old in 2025.

What condition is SD050 over Nelson Ck in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in June 2023.

How much traffic does SD050 over Nelson Ck carry?

About 284 vehicles per day (2024 count), of which roughly 11% are trucks.

How long is SD050 over Nelson Ck?

The structure is 106 ft (32.3 m) long with a longest span of 38 ft (11.5 m) and a deck 43 ft wide.

Who owns SD050 over Nelson Ck?

It is owned by the State Highway Agency.