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420TH St over Drainage

Pottawattamie County, Iowa · rated Good in the 2025 National Bridge Inventory

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

420TH St over Drainage in Pottawattamie County, Iowa, is rated in good condition in the 2025 National Bridge Inventory (as of August 20, 2026).
Its lowest-rated component is the deck, rated 8 (very good condition) on the 0-9 scale.
It was built in 2011, making it 14 years old at the 2025 inventory.
It carries about 29 vehicles a day (traffic count year 2021).
Its listed owner is the county highway agency.
It is one of 219 of the 557 inventoried bridges in Pottawattamie County rated good (39.3%); 50 (9.0%) are rated poor.
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.

Component ratings


Structure	Concrete stringer or multi-beam girder
Length	about 29 ft
Location	00000
NBI structure number	000000000287472
Condition class	Good

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

Bridge	Built	Vehicles/day	Condition
I-480 & US 6 over Missouri River & RR	1966	53,700	Fair
I-80 EB over Missouri River Rd & RR	1972	31,550	Fair
I 80 & US 6 over Little Mosquito Creek	1966	31,100	Fair
I 80 WB over Missouri Rvr Rd RR	2010	25,250	Good
I 29 SB over I-80 & I-29 Interchange	2014	23,900	Good
I-80 over Bedell Creek	1965	23,800	Fair