US Bridges

HWY 99 over Drainage Ditch

Fair

Louisa County, Iowa · 074033608 · Structure no. 000000000034190

Built
1954
71 years old
Condition
Fair
inspected June 2023
Type
Culvert
Concrete Continuous
Length
25 ft
2 main spans
Daily traffic
490
2022 count
Owner
County
County Highway Agency

About this bridge

HWY 99 over Drainage Ditch is a concrete continuous culvert carrying HWY 99 over Drainage Ditch in Louisa County, Iowa. It was built in 1954, so it is 71 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 5 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 490 vehicles a day, roughly 19% of them trucks, projected to reach 490 by 2043. The structure is 25 ft (7.6 m) long and 39 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesHWY 99
CrossesDrainage Ditch
Location074033608
RouteCounty Highway 0
CountyLouisa County
StateIowa
Coordinates41.1735, -91.15124
Functional classRural Minor Arterial

Condition and inspection

Fair

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

ComponentRatingMeaning
Channel and channel protection7 GoodSome minor problems.
Culvert5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating62.2 US tons
Inventory rating37.3 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans2
Design loadH 20
Structure length25 ft (7.6 m)
Longest span12 ft (3.7 m)
Deck width39 ft (11.9 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic490 (2022)
Projected traffic490 by 2043
Trucks19%
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 HWY 99 over Drainage Ditch built?

It was built in 1954, making it 71 years old in 2025.

What condition is HWY 99 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 June 2023.

How much traffic does HWY 99 over Drainage Ditch carry?

About 490 vehicles per day (2022 count), of which roughly 19% are trucks.

How long is HWY 99 over Drainage Ditch?

The structure is 25 ft (7.6 m) long with a longest span of 12 ft (3.7 m) and a deck 39 ft wide.

Who owns HWY 99 over Drainage Ditch?

It is owned by the County Highway Agency.