US Bridges

Ia 25 over Summit Lake

Fair

Union County, Iowa · 2.6 Mi. N of N Jct. US 34 · Structure no. 000000000050171

Built
1976
49 years old
Condition
Fair
inspected August 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
146 ft
3 main spans
Daily traffic
1,950
2022 count
Owner
State
State Highway Agency

About this bridge

Ia 25 over Summit Lake is a prestressed concrete stringer/multi-beam or girder carrying Ia 25 over Summit Lake in Union 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 1,950 vehicles a day, roughly 10% of them trucks, projected to reach 1,950 by 2044. The structure is 146 ft (44.5 m) long and 48 ft wide.

Location

Open in Google Maps
CarriesIa 25
CrossesSummit Lake
Location2.6 Mi. N of N Jct. US 34
RouteState Highway 25
CountyUnion County
StateIowa
Coordinates41.07122, -94.39233
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionAugust 2024
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 geometry8: Equal to present desirable criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating57.2 US tons
Inventory rating29.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length146 ft (44.5 m)
Longest span57 ft (17.4 m)
Deck width48 ft (14.5 m)
Roadway width44 ft (13.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,950 (2022)
Projected traffic1,950 by 2044
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed—
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 25 over Summit Lake built?

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

What condition is Ia 25 over Summit Lake 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 August 2024.

How much traffic does Ia 25 over Summit Lake carry?

About 1,950 vehicles per day (2022 count), of which roughly 10% are trucks.

How long is Ia 25 over Summit Lake?

The structure is 146 ft (44.5 m) long with a longest span of 57 ft (17.4 m) and a deck 48 ft wide.

Who owns Ia 25 over Summit Lake?

It is owned by the State Highway Agency.