US Bridges

US 18 over Drainage Ditch

Fair

Lyon County, Iowa · 3.8 Mi. W of Ia 182 · Structure no. 000000000034491

Built
1975
50 years old
Condition
Fair
inspected February 2023
Type
Slab
Concrete Continuous
Length
113 ft
3 main spans
Daily traffic
2,130
2022 count
Owner
State
State Highway Agency

About this bridge

US 18 over Drainage Ditch is a concrete continuous slab carrying US 18 over Drainage Ditch in Lyon County, Iowa. It was built in 1975, so it is 50 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 2,130 vehicles a day, roughly 20% of them trucks, projected to reach 2,130 by 2042. The structure is 113 ft (34.4 m) long and 47 ft wide. If it were closed, the detour would be 9.9 mi (16 km).

CarriesUS 18
CrossesDrainage Ditch
Location3.8 Mi. W of Ia 182
RouteU.S. Route 18
StateIowa
Coordinates43.30571, -96.50615
Functional classRural Principal Arterial - Other

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 protection7 GoodSome minor problems.
Last inspectionFebruary 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating67.9 US tons
Inventory rating40.7 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length113 ft (34.4 m)
Longest span43 ft (13.1 m)
Deck width47 ft (14.4 m)
Roadway width44 ft (13.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,130 (2022)
Projected traffic2,130 by 2042
Trucks20%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed9.9 mi (16 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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 US 18 over Drainage Ditch built?

It was built in 1975, making it 50 years old in 2025.

What condition is US 18 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 February 2023.

How much traffic does US 18 over Drainage Ditch carry?

About 2,130 vehicles per day (2022 count), of which roughly 20% are trucks.

How long is US 18 over Drainage Ditch?

The structure is 113 ft (34.4 m) long with a longest span of 43 ft (13.1 m) and a deck 47 ft wide.

Who owns US 18 over Drainage Ditch?

It is owned by the State Highway Agency.