US Bridges

X Ave over Onion Creek

Good

Boone County, Iowa · 084252502 · Structure no. 000000000077691

Built
2023
2 years old
Condition
Good
inspected May 2024
Type
Slab
Concrete Continuous
Length
81 ft
3 main spans
Daily traffic
50
2023 count
Owner
County
County Highway Agency

About this bridge

X Ave over Onion Creek is a concrete continuous slab carrying X Ave over Onion Creek in Boone County, Iowa. It was built in 2023, so it is 2 years old, younger than the Iowa average of 45.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 9 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 50 vehicles a day, roughly 18% of them trucks, projected to reach 50 by 2044. The structure is 81 ft (24.7 m) long and 33 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesX Ave
CrossesOnion Creek
Location084252502
RouteCounty Highway 0
CountyBoone County
StateIowa
Coordinates42.05634, -93.71805
Functional classRural Local

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck9 ExcellentNo problems noted.
Superstructure9 ExcellentNo problems noted.
Substructure9 ExcellentNo problems noted.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionMay 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation9: Superior to present desirable criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating55.3 US tons
Inventory rating42.9 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHL 93
Structure length81 ft (24.7 m)
Longest span31 ft (9.4 m)
Deck width33 ft (10.1 m)
Roadway width31 ft (9.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic50 (2023)
Projected traffic50 by 2044
Trucks18%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedOther structural work, including hydraulic replacements
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was X Ave over Onion Creek built?

It was built in 2023, making it 2 years old in 2025.

What condition is X Ave over Onion Creek in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in May 2024.

How much traffic does X Ave over Onion Creek carry?

About 50 vehicles per day (2023 count), of which roughly 18% are trucks.

How long is X Ave over Onion Creek?

The structure is 81 ft (24.7 m) long with a longest span of 31 ft (9.4 m) and a deck 33 ft wide.

Who owns X Ave over Onion Creek?

It is owned by the County Highway Agency.