US Bridges

459th Avenue over Boswell Diversion Ditch

FairPosted for load

Hamlin County, South Dakota · 6.5S of Castlewood · Structure no. 000000029230115

Built
1956
69 years old
Condition
Fair
inspected July 2024
Type
Slab
Concrete Continuous
Length
106 ft
3 main spans
Daily traffic
253
2022 count
Owner
County
County Highway Agency

About this bridge

459th Avenue over Boswell Diversion Ditch is a concrete continuous slab carrying 459th Avenue over Boswell Diversion Ditch in Hamlin 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. Its operating status is: posted for load restriction.

It carries about 253 vehicles a day, roughly 2% of them trucks, projected to reach 253 by 2032. The structure is 106 ft (32.3 m) long and 28 ft wide. If it were closed, the detour would be 9.9 mi (16 km).

Location

Open in Google Maps
Carries459th Avenue
CrossesBoswell Diversion Ditch
Location6.5S of Castlewood
RouteCounty Highway 0
CountyHamlin County
StateSouth Dakota
Coordinates44.63709, -97.02703
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 inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation4: Meets minimum tolerable limits to be 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 rating19.1 US tons
Inventory rating14.7 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadH 15
Structure length106 ft (32.3 m)
Longest span40 ft (12.2 m)
Deck width28 ft (8.6 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic253 (2022)
Projected traffic253 by 2032
Trucks2%
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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$2.3 million (2024 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was 459th Avenue over Boswell Diversion Ditch built?

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

What condition is 459th Avenue over Boswell Diversion Ditch 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 459th Avenue over Boswell Diversion Ditch carry?

About 253 vehicles per day (2022 count), of which roughly 2% are trucks.

How long is 459th Avenue over Boswell Diversion Ditch?

The structure is 106 ft (32.3 m) long with a longest span of 40 ft (12.2 m) and a deck 28 ft wide.

Who owns 459th Avenue over Boswell Diversion Ditch?

It is owned by the County Highway Agency.