Home › South Dakota › Aurora County › 370 Ave over I090

370 Ave over I090

Aurora County, South Dakota · rated Fair in the 2025 National Bridge Inventory

United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled August 20, 2026

370 Ave over I090 in Aurora County, South Dakota, is rated in fair condition in the 2025 National Bridge Inventory (as of August 20, 2026).
Its lowest-rated component is the superstructure, rated 6 (satisfactory condition) on the 0-9 scale.
It was built in 1965, making it 60 years old at the 2025 inventory.
It carries about 75 vehicles a day (traffic count year 2023).
Its listed owner is the state highway agency.
It is one of 29 of the 61 inventoried bridges in Aurora County rated fair (47.5%); 7 (11.5%) are rated poor.
A fair rating means the lowest-rated major component scores 5 or 6 on FHWA's 0-9 scale: some deterioration or minor section loss, but the structure is sound. It is the middle class, not a warning.

Component ratings


Structure	Continuous steel stringer or multi-beam girder
Length	about 253 ft
Location	Aurora & Brule Co Line
NBI structure number	000000002000135
Condition class	Fair

Source: FHWA National Bridge Inventory, 2025 data as reported by the South Dakota department of transportation.

Bridge	Built	Vehicles/day	Condition
I090 over Ck	1965	9,890	Fair
I090 W over Platte Ck	1964	4,425	Fair
I090 E over Platte Ck	1964	4,425	Fair
US281 over I090	1965	1,694	Fair
US281 over Ck	2007	1,434	Good
US281 over West Br Firesteel Ck	1959	1,284	Fair