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US 20 over Miss. River Hwy & RR

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

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

US 20 over Miss. River Hwy & RR in Dubuque County, Iowa, 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 1943 and reconstructed in 1992, making it 82 years old at the 2025 inventory.
It carries about 17,700 vehicles a day (traffic count year 2022).
Its listed owner is the state highway agency.
It is one of 141 of the 346 inventoried bridges in Dubuque County rated fair (40.8%); 25 (7.2%) 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 through arch
Length	about 5,759 ft
Location	In Dubuque
NBI structure number	000000000023880
Condition class	Fair

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

Bridge	Built	Vehicles/day	Condition
US 20 over N Branch Catfish Creek	1939	33,600	Fair
US 61 & 151 over Peosta Chl & City St	1991	22,300	Fair
US 61 & 151 over Mississippi River Island	1982	20,400	Fair
US 20 US 52 over Drainage Ditch	1957	18,500	Fair
EB US 20 over Mid Br Catfish Ck Cc RR	1995	14,300	Good
WB US 20 over Mid Br Catfish Ck Cc RR	1961	14,300	Fair