US Bridges

I 35 SB over South Skunk River

Good

Story County, Iowa · 2.6 Mi. S of Jct. U.S. 30 · Structure no. 000000000049191

Built
2017
8 years old
Condition
Good
inspected July 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
378 ft
4 main spans
Daily traffic
23,300
2022 count
Owner
State
State Highway Agency

About this bridge

I 35 SB over South Skunk River is a prestressed concrete stringer/multi-beam or girder carrying I 35 SB over South Skunk River in Story County, Iowa. It was built in 2017, so it is 8 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 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 23,300 vehicles a day, roughly 19% of them trucks, projected to reach 23,300 by 2043. The structure is 378 ft (115.1 m) long and 63 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesI 35 SB
CrossesSouth Skunk River
Location2.6 Mi. S of Jct. U.S. 30
RouteInterstate 35
StateIowa
Coordinates41.97145, -93.57067
Functional classRural Principal Arterial - Interstate

Condition and inspection

Good

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

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation8: Equal to present desirable criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating46.4 US tons
Inventory rating35.7 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans4
Design loadHL 93
Structure length378 ft (115.1 m)
Longest span107 ft (32.5 m)
Deck width63 ft (19.3 m)
Roadway width60 ft (18.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic23,300 (2022)
Projected traffic23,300 by 2043
Trucks19%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

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 I 35 SB over South Skunk River built?

It was built in 2017, making it 8 years old in 2025.

What condition is I 35 SB over South Skunk River 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 July 2023.

How much traffic does I 35 SB over South Skunk River carry?

About 23,300 vehicles per day (2022 count), of which roughly 19% are trucks.

How long is I 35 SB over South Skunk River?

The structure is 378 ft (115.1 m) long with a longest span of 107 ft (32.5 m) and a deck 63 ft wide.

Who owns I 35 SB over South Skunk River?

It is owned by the State Highway Agency.