US Bridges

Mallard Ave over Small Natural Stream

Fair

Plymouth County, Iowa · 093452329 · Structure no. 000000000040041

Built
1974
51 years old
Condition
Fair
inspected June 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
59 ft
1 main span
Daily traffic
5
2022 count
Owner
County
County Highway Agency

About this bridge

Mallard Ave over Small Natural Stream is a prestressed concrete stringer/multi-beam or girder carrying Mallard Ave over Small Natural Stream in Plymouth County, Iowa. It was built in 1974, so it is 51 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 5 vehicles a day, projected to reach 5 by 2044. The structure is 59 ft (18 m) long and 47 ft wide. If it were closed, the detour would be 18 mi (29 km).

Location

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CarriesMallard Ave
CrossesSmall Natural Stream
Location093452329
RouteCounty Highway 0
CountyPlymouth County
StateIowa
Coordinates42.8543, -96.12661
Functional classRural Local

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.
Substructure8 Very GoodNo problems noted.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment5: Somewhat better than minimum adequacy to tolerate being left in place as is
Operating rating49.8 US tons
Inventory rating29.9 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length59 ft (18 m)
Longest span55 ft (16.8 m)
Deck width47 ft (14.4 m)
Roadway width44 ft (13.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic5 (2022)
Projected traffic5 by 2044
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed18 mi (29 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Mallard Ave over Small Natural Stream built?

It was built in 1974, making it 51 years old in 2025.

What condition is Mallard Ave over Small Natural Stream 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 Mallard Ave over Small Natural Stream carry?

About 5 vehicles per day (2022 count).

How long is Mallard Ave over Small Natural Stream?

The structure is 59 ft (18 m) long with a longest span of 55 ft (16.8 m) and a deck 47 ft wide.

Who owns Mallard Ave over Small Natural Stream?

It is owned by the County Highway Agency.