Home › Iowa › Monona County › Ia 37 over East Willow River

Ia 37 over East Willow River

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

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

Ia 37 over East Willow River in Monona 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 7 (good condition) on the 0-9 scale.
It was built in 1996, making it 29 years old at the 2025 inventory.
It carries about 830 vehicles a day (traffic count year 2022).
Its listed owner is the state highway agency.
It is one of 60 of the 160 inventoried bridges in Monona County rated good (37.5%); 41 (25.6%) 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	Prestressed concrete stringer or multi-beam girder
Length	about 300 ft
Location	0.7 mi. E of SR E54
NBI structure number	000000000036721
Condition class	Good

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

Bridge	Built	Vehicles/day	Condition
NB I-29 over Robinson Ditch	2011	7,800	Good
SB I-29 over Robinson Ditch	2009	7,800	Good
NB I-29 over Cleghorn Creek	2012	7,250	Good
SB I-29 over Cleghorn Creek	2011	7,250	Good
Ia 175 over Mccandlesscleghorn Ditch	2023	5,300	Good
Ia 175 over I-29	1959	4,090	Poor