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620TH AVE/S14 over Grant Open Ditch Ext 5

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

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

620TH AVE/S14 over Grant Open Ditch Ext 5 in Story 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 6 (satisfactory condition) on the 0-9 scale.
It was built in 1977, making it 48 years old at the 2025 inventory.
It carries about 988 vehicles a day (traffic count year 2022).
Its listed owner is the county highway agency.
It is one of 160 of the 302 inventoried bridges in Story County rated fair (53.0%); 40 (13.2%) 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	Steel stringer or multi-beam girder
Length	about 54 ft
Location	083223102
NBI structure number	000000000314661
Condition class	Fair

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

Bridge	Built	Vehicles/day	Condition
I-35 over Ballard Creek	1964	48,300	Fair
I-35 over Walnut Creek	1964	48,300	Fair
I 35 over South Skunk Rvr Overflow	2017	48,300	Good
I-35 over Drainage Ditch	1967	28,300	Good
US 69 over Ioway Creek	1924	24,600	Good
NB I-35 over Bike Path	1964	24,150	Fair