31490 477TH Ave over Br Brule Ck

Union County, South Dakota · rated Poor in the 2025 National Bridge Inventory

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

• 31490 477TH Ave over Br Brule Ck in Union County, South Dakota, is rated in poor condition in the 2025 National Bridge Inventory (as of August 20, 2026).
• Its lowest-rated component is the culvert, rated 4 (poor condition) on the 0-9 scale.
• It was built in 1955, making it 70 years old at the 2025 inventory.
• It carries about 300 vehicles a day (traffic count year 2022).
• Its listed owner is the county highway agency.
• It is one of 41 of the 169 inventoried bridges in Union County rated poor (24.3%); 41 (24.3%) 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 poor (culvert 5 to 4).
• Its most recent inspection on record is dated August 2024, on a 24-month routine inspection cycle.
• A poor rating means at least one major component - deck, superstructure, or substructure - is rated 4 or lower on FHWA's 0-9 scale. It does not by itself mean the bridge is unsafe; bridges judged unsafe are closed or load-restricted by their owners.

View this bridge on a map → (42.82293, -96.66573)

Component ratings

Bridge details

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

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