US Bridges

L20 Loess Hills over Drainage Ditch

Fair

Harrison County, Iowa · 078442710 · Structure no. 000000000027791

Built
1976
49 years old
Condition
Fair
inspected January 2024
Type
Slab
Concrete Continuous
Length
73 ft
3 main spans
Daily traffic
1,065
2022 count
Owner
County
County Highway Agency

About this bridge

L20 Loess Hills over Drainage Ditch is a concrete continuous slab carrying L20 Loess Hills over Drainage Ditch in Harrison County, Iowa. It was built in 1976, so it is 49 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 1,065 vehicles a day, roughly 11% of them trucks, projected to reach 1,065 by 2044. The structure is 73 ft (22.3 m) long and 39 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

CarriesL20 Loess Hills
CrossesDrainage Ditch
Location078442710
RouteCounty Highway 0
StateIowa
Coordinates41.52994, -95.88454
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJanuary 2024
Inspection intervalevery 24 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 adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating50.9 US tons
Inventory rating30.6 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length73 ft (22.3 m)
Longest span28 ft (8.5 m)
Deck width39 ft (12 m)
Roadway width36 ft (10.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,065 (2022)
Projected traffic1,065 by 2044
Trucks11%
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 L20 Loess Hills over Drainage Ditch built?

It was built in 1976, making it 49 years old in 2025.

What condition is L20 Loess Hills over Drainage Ditch 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 January 2024.

How much traffic does L20 Loess Hills over Drainage Ditch carry?

About 1,065 vehicles per day (2022 count), of which roughly 11% are trucks.

How long is L20 Loess Hills over Drainage Ditch?

The structure is 73 ft (22.3 m) long with a longest span of 28 ft (8.5 m) and a deck 39 ft wide.

Who owns L20 Loess Hills over Drainage Ditch?

It is owned by the County Highway Agency.