US Bridges

Ia 4 over Mosquito Creek

Good

Guthrie County, Iowa · 0.3 Mi. S of S JCT Ia 141 · Structure no. 000000000026071

Built
2001
24 years old
Condition
Good
inspected November 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
100 ft
1 main span
Daily traffic
1,260
2022 count
Owner
State
State Highway Agency

About this bridge

Ia 4 over Mosquito Creek is a prestressed concrete stringer/multi-beam or girder carrying Ia 4 over Mosquito Creek in Guthrie County, Iowa. It was built in 2001, so it is 24 years old, younger than the Iowa average of 45.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 1,260 vehicles a day, roughly 22% of them trucks, projected to reach 1,260 by 2044. The structure is 100 ft (30.5 m) long and 43 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

Open in Google Maps
CarriesIa 4
CrossesMosquito Creek
Location0.3 Mi. S of S JCT Ia 141
RouteState Highway 4
CountyGuthrie County
StateIowa
Coordinates41.83218, -94.36731
Functional classRural Minor Arterial

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection7 GoodSome minor problems.
Last inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation8: Equal to present desirable criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating90.8 US tons
Inventory rating48.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length100 ft (30.5 m)
Longest span100 ft (30.5 m)
Deck width43 ft (13 m)
Roadway width39 ft (11.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,260 (2022)
Projected traffic1,260 by 2044
Trucks22%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 km)
TollOn a free road
National Highway SystemNo

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 Ia 4 over Mosquito Creek built?

It was built in 2001, making it 24 years old in 2025.

What condition is Ia 4 over Mosquito Creek in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in November 2024.

How much traffic does Ia 4 over Mosquito Creek carry?

About 1,260 vehicles per day (2022 count), of which roughly 22% are trucks.

How long is Ia 4 over Mosquito Creek?

The structure is 100 ft (30.5 m) long with a longest span of 100 ft (30.5 m) and a deck 43 ft wide.

Who owns Ia 4 over Mosquito Creek?

It is owned by the State Highway Agency.