US Bridges

470th Avenue over Ck

PoorPosted for load

Brookings County, South Dakota · 14.3N & 1W Brookings · Structure no. 000000006160017

Built
1930
95 years old
Condition
Poor
inspected September 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
22 ft
1 main span
Daily traffic
92
2022 count
Owner
County
County Highway Agency

About this bridge

470th Avenue over Ck is a steel stringer/multi-beam or girder carrying 470th Avenue over Ck in Brookings County, South Dakota. It was built in 1930, so it is 95 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 poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. Its operating status is: posted for load restriction.

It carries about 92 vehicles a day, roughly 2% of them trucks, projected to reach 92 by 2032. The structure is 22 ft (6.7 m) long and 19 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Carries470th Avenue
CrossesCk
Location14.3N & 1W Brookings
RouteCounty Highway 0
Coordinates44.51853, -96.80673
Functional classRural Local

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

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.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation2: Basically intolerable, requiring high priority of replacement
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating13.3 US tons
Inventory rating8 US tons

Structure

MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadUnknown
Structure length22 ft (6.7 m)
Longest span21 ft (6.4 m)
Deck width19 ft (5.9 m)
Roadway width18 ft (5.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic92 (2022)
Projected traffic92 by 2032
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 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$840,000 (2024 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was 470th Avenue over Ck built?

It was built in 1930, making it 95 years old in 2025.

What condition is 470th Avenue over Ck in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in September 2024.

How much traffic does 470th Avenue over Ck carry?

About 92 vehicles per day (2022 count), of which roughly 2% are trucks.

How long is 470th Avenue over Ck?

The structure is 22 ft (6.7 m) long with a longest span of 21 ft (6.4 m) and a deck 19 ft wide.

Who owns 470th Avenue over Ck?

It is owned by the County Highway Agency.