I090 W over US183

Lyman County, South Dakota · rated Good in the 2025 National Bridge Inventory

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

• I090 W over US183 in Lyman County, South Dakota, is rated in good condition in the 2025 National Bridge Inventory (as of August 20, 2026).
• Its lowest-rated component is the deck, rated 7 (good condition) on the 0-9 scale.
• It was built in 1970, making it 55 years old at the 2025 inventory.
• It carries about 3,839 vehicles a day (traffic count year 2024).
• Its listed owner is the state highway agency.
• It is one of 46 of the 114 inventoried bridges in Lyman County rated good (40.4%); 12 (10.5%) are rated poor.
• Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
• It was rated fair in the 2024 inventory and is now good (superstructure 8 to 7, deck 6 to 7).
• Its most recent inspection on record is dated April 2024, on a 24-month routine inspection cycle.
• A good rating means every major component - deck, superstructure, substructure, or culvert - is rated 7 or higher on FHWA's 0-9 scale: no more than minor problems.

View this bridge on a map → (43.89827, -100.04546)

Component ratings

Bridge details

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

Busiest bridges in Lyman County

All bridges nearby: Lyman County, SD bridge conditions · every bridge in Lyman County · South Dakota bridges.

Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.