US Bridges

20th Ave over N Fork Buffalo Creek

Fair

Winnebago County, Iowa · 098260406 · Structure no. 000000000344651

Built
1989
36 years old
Condition
Fair
inspected March 2023
Type
Slab
Concrete Continuous
Length
78 ft
3 main spans
Daily traffic
409
2022 count
Owner
County
County Highway Agency

About this bridge

20th Ave over N Fork Buffalo Creek is a concrete continuous slab carrying 20th Ave over N Fork Buffalo Creek in Winnebago County, Iowa. It was built in 1989, so it is 36 years old, younger than the Iowa average of 45.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 409 vehicles a day, roughly 23% of them trucks, projected to reach 409 by 2043. The structure is 78 ft (23.8 m) long and 33 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
Carries20th Ave
CrossesN Fork Buffalo Creek
Location098260406
RouteCounty Highway 0
CountyWinnebago County
StateIowa
Coordinates43.33455, -93.93171
Functional classRural Major Collector

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionMarch 2023
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating83.9 US tons
Inventory rating50.2 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length78 ft (23.8 m)
Longest span29 ft (8.8 m)
Deck width33 ft (10.1 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic409 (2022)
Projected traffic409 by 2043
Trucks23%
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$30,000 (2024 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was 20th Ave over N Fork Buffalo Creek built?

It was built in 1989, making it 36 years old in 2025.

What condition is 20th Ave over N Fork Buffalo Creek in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in March 2023.

How much traffic does 20th Ave over N Fork Buffalo Creek carry?

About 409 vehicles per day (2022 count), of which roughly 23% are trucks.

How long is 20th Ave over N Fork Buffalo Creek?

The structure is 78 ft (23.8 m) long with a longest span of 29 ft (8.8 m) and a deck 33 ft wide.

Who owns 20th Ave over N Fork Buffalo Creek?

It is owned by the County Highway Agency.