US Bridges

L 20 over Pigeon Creek

Fair

Pottawattamie County, Iowa · 076430612 · Structure no. 000000000044001

Built
1977
48 years old
Condition
Fair
inspected June 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
271 ft
3 main spans
Daily traffic
2,430
2022 count
Owner
County
County Highway Agency

About this bridge

L 20 over Pigeon Creek is a prestressed concrete stringer/multi-beam or girder carrying L 20 over Pigeon Creek in Pottawattamie County, Iowa. It was built in 1977, so it is 48 years old, older 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 2,430 vehicles a day, roughly 12% of them trucks, projected to reach 2,430 by 2043. The structure is 271 ft (82.6 m) long and 35 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesL 20
CrossesPigeon Creek
Location076430612
RouteCounty Highway 0
CountyPottawattamie County
StateIowa
Coordinates41.40642, -95.8339
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure8 Very GoodNo problems noted.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 2023
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment5: Somewhat better than minimum adequacy to tolerate being left in place as is
Operating rating48.9 US tons
Inventory rating36 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length271 ft (82.6 m)
Longest span95 ft (29 m)
Deck width35 ft (10.7 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,430 (2022)
Projected traffic2,430 by 2043
Trucks12%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was L 20 over Pigeon Creek built?

It was built in 1977, making it 48 years old in 2025.

What condition is L 20 over Pigeon 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 June 2023.

How much traffic does L 20 over Pigeon Creek carry?

About 2,430 vehicles per day (2022 count), of which roughly 12% are trucks.

How long is L 20 over Pigeon Creek?

The structure is 271 ft (82.6 m) long with a longest span of 95 ft (29 m) and a deck 35 ft wide.

Who owns L 20 over Pigeon Creek?

It is owned by the County Highway Agency.