Home › Iowa › Polk County › I-235 over Drainage Ditch

I-235 over Drainage Ditch

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

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

I-235 over Drainage Ditch in Polk County, Iowa, is rated in fair condition in the 2025 National Bridge Inventory (as of August 20, 2026).
Its lowest-rated component is the culvert, rated 6 (satisfactory condition) on the 0-9 scale.
It was built in 1966 and reconstructed in 2004, making it 59 years old at the 2025 inventory.
It carries about 118,600 vehicles a day (traffic count year 2022).
Its listed owner is the state highway agency.
It is one of 195 of the 548 inventoried bridges in Polk County rated fair (35.6%); 34 (6.2%) 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

Component	Rating (2025)	FHWA scale meaning
Culvert	6	Satisfactory condition


Structure	Continuous concrete culvert
Length	about 46 ft
Location	0.4 Mile East of Iowa 28
NBI structure number	000000000606140
Condition class	Fair

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

Bridge	Built	Vehicles/day	Condition
I-235 & 17TH St over Blue Creek	1968	113,200	Fair
I 235 over Des Moines Rvr Rbrtraydr	1962	88,200	Good
I-35 & I-80 over N Walnut Creek	1958	81,600	Fair
I 35 over Trib to Four Mile Creek	2018	58,300	Good
EB I-235 over Walnut Creek	1968	58,050	Fair
WB I-235 over Walnut Creek	1968	58,050	Fair