Structure 6170056 · Brookings County, SD

471st Street over North Deer Ck

Carries 471st Street over North Deer Ck, 10.4n Brookings.

Overall conditionPoor

Set by its lowest-rated component: Deck at 4 of 9.

How ratings work
Decksets the rating4/9 · Poor
Superstructure5/9 · Fair
Substructure5/9 · Fair
Channelnot part of overall7/9 · Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
CAR · 15 FT74 FT OVERALL25 FT0ELEVATION · LENGTHS TO SCALE
Deck 4/9 · sets the ratingSuperstructure 5/9Substructure 5/9

74 ft end to end, longest span 36 ft. Lengths and the car on the deck are drawn to the same scale. Each part is colored by its latest inspection rating. The inventory records lengths but not heights or the layout of the shorter spans, so those are drawn as typical for a multi-beam bridge.

Built1925rebuilt 1940
Length74.1 ft22.6 m
Daily traffic462counted 2022
Last inspectedOctober 2024every 12 months

Location

StateSouth Dakota
CountyBrookings
Location10.4n Brookings
Carries471st Street
CrossesNorth Deer Ck
Coordinates44.46229, -96.78720

Physical Characteristics

MaterialSteel
DesignStringer/Multi-beam
Total Length74.1 ft (22.6 m)
Max Span36.1 ft (11 m)
Deck Width33.1 ft (10.1 m)
Deck Area228.3 sq m
Main Spans2
Year Built1925 (reconstructed 1940)

Traffic

Avg Daily Traffic462 (2022)
Truck Traffic3%
Lanes On Bridge2

Inspection & Ownership

Last InspectionOctober 2024
Inspection FrequencyEvery 12 months
OwnerCounty Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour Critical3 — Scour critical
Structure Number000000006170056

How Bridge Ratings Work

Inspectors rate each major part of a bridge (the deck you drive on, the superstructure of beams that holds it up, and the substructure of piers and abutments beneath) on a 0–9 scale. A bridge's overall condition is its lowest of those ratings, so one deteriorated component makes the whole bridge "poor."

0Failed
1Imminent failure
2Critical
3Serious
4Poor
5Fair
6Satisfactory
7Good
8Very good
9Excellent
Good · lowest component 7–9
Fair · lowest component 5–6
Poor · lowest component 0–4

A poor rating is not a closure. It means the bridge is flagged for priority repair or replacement; bridges judged unsafe are closed or posted with weight limits. The waterway (channel) rating is reported, but it does not count toward the overall classification.

Nearby Bridges