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FM over Nishnabotna River (ef)

Audubon County, Iowa · rated Fair in the 2025 National Bridge Inventory

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

FM over Nishnabotna River (ef) in Audubon County, Iowa, is rated in fair condition in the 2025 National Bridge Inventory (as of August 20, 2026).
Its lowest-rated component is the substructure, rated 5 (fair condition) on the 0-9 scale.
It was built in 1963, making it 62 years old at the 2025 inventory.
It carries about 110 vehicles a day (traffic count year 2022).
Its listed owner is the county highway agency.
It is one of 96 of the 204 inventoried bridges in Audubon County rated fair (47.1%); 37 (18.1%) 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	Prestressed concrete stringer or multi-beam girder
Length	about 43 ft
Location	080361503
NBI structure number	000000000068860
Condition class	Fair

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

Bridge	Built	Vehicles/day	Condition
US 71 over Stream	1983	3,700	Good
US 71 over Bluegrass Creek	2006	3,080	Good
US 71 over East Nishnabotna River	1959	2,470	Fair
US 71 over Stream	1923	2,380	Fair
US 71 over Stream	1961	2,380	Fair
US 71 over Stream	1961	2,380	Fair