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FM 255TH St over Boylan Creek

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

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

FM 255TH St over Boylan Creek in Franklin County, Iowa, is rated in good condition in the 2025 National Bridge Inventory (as of August 20, 2026).
Its lowest-rated component is the culvert, rated 7 (good condition) on the 0-9 scale.
It was built in 1991, making it 34 years old at the 2025 inventory.
It carries about 658 vehicles a day (traffic count year 2022).
Its listed owner is the county highway agency.
It is one of 103 of the 227 inventoried bridges in Franklin County rated good (45.4%); 28 (12.3%) are rated poor.
Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
Its condition class and component ratings are unchanged from the 2024 inventory.
Its most recent inspection on record is dated July 2023, on a 48-month routine inspection cycle.
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

Component	Rating (2024)	Rating (2025)	FHWA scale meaning
Culvert	7	7	Good condition


Structure	Continuous concrete culvert
Length	about 37 ft
Location	093190303
NBI structure number	000000000363355
Condition class	Good
Traffic status (item 41)	Open, no restriction
Last inspection (item 90)	July 2023
Inspection interval (item 91)	48 months
Scour (item 113)	8: foundations stable, scour above the top of the footing

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

Bridge	Built	Vehicles/day	Condition
I-35 over Drainage Ditch	1972	17,300	Good
I-35 over Drainage Ditch	1973	17,000	Good
I-35 over Drainage Ditch	1972	16,900	Fair
I-35 over Stream	1974	15,300	Fair
I-35 over Drainage Ditch NO.48	1974	15,100	Good
NB I-35 over Buffalo Creek	1973	8,600	Good