US Bridges

Diamond Rd. over Alkali Ck

Fair

Meade County, South Dakota · 11E & 2.3S Sturgis · Structure no. 000000047140453

Built
1978
47 years old
Condition
Fair
inspected July 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
41 ft
1 main span
Daily traffic
10
2022 count
Owner
County
County Highway Agency

About this bridge

Diamond Rd. over Alkali Ck is a steel stringer/multi-beam or girder carrying Diamond Rd. over Alkali Ck in Meade County, South Dakota. It was built in 1978, so it is 47 years old, younger 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 10 vehicles a day, roughly 2% of them trucks, projected to reach 10 by 2032. The structure is 41 ft (12.5 m) long and 15 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

Location

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CarriesDiamond Rd.
CrossesAlkali Ck
Location11E & 2.3S Sturgis
RouteCounty Highway 0
CountyMeade County
StateSouth Dakota
Coordinates44.38305, -103.28712
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment5: Somewhat better than minimum adequacy to tolerate being left in place as is
Operating rating30.4 US tons
Inventory rating22.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckWood or timber
Main spans1
Design loadHS 20
Structure length41 ft (12.5 m)
Longest span38 ft (11.6 m)
Deck width15 ft (4.6 m)
Roadway width14 ft (4.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic10 (2022)
Projected traffic10 by 2032
Trucks2%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.8 mi (159 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 proposedOther structural work, including hydraulic replacements
Estimated improvement cost$25,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Diamond Rd. over Alkali Ck built?

It was built in 1978, making it 47 years old in 2025.

What condition is Diamond Rd. over Alkali 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 2024.

How much traffic does Diamond Rd. over Alkali Ck carry?

About 10 vehicles per day (2022 count), of which roughly 2% are trucks.

How long is Diamond Rd. over Alkali Ck?

The structure is 41 ft (12.5 m) long with a longest span of 38 ft (11.6 m) and a deck 15 ft wide.

Who owns Diamond Rd. over Alkali Ck?

It is owned by the County Highway Agency.