US Bridges

SB I-35 over US 18

Fair

Cerro Gordo County, Iowa · At N Jct. of US 18 · Structure no. 000000000019240

Built
1971
54 years old
Condition
Fair
inspected April 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
275 ft
4 main spans
Daily traffic
8,400
2022 count
Owner
State
State Highway Agency

About this bridge

SB I-35 over US 18 is a steel continuous stringer/multi-beam or girder carrying SB I-35 over US 18 in Cerro Gordo County, Iowa. It was built in 1971, so it is 54 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 8,400 vehicles a day, roughly 33% of them trucks, projected to reach 8,400 by 2044. The structure is 275 ft (83.8 m) long and 43 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesSB I-35
CrossesUS 18
LocationAt N Jct. of US 18
RouteInterstate 35
CountyCerro Gordo County
StateIowa
Coordinates43.14669, -93.35601
Functional classUrban Principal Arterial - Interstate

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating71 US tons
Inventory rating42 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length275 ft (83.8 m)
Longest span88 ft (26.8 m)
Deck width43 ft (13.2 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic8,400 (2022)
Projected traffic8,400 by 2044
Trucks33%
Lanes on structure2
Traffic directionOne-way traffic
CarriesOverpass structure at an interchange
CrossesHighway
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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was SB I-35 over US 18 built?

It was built in 1971, making it 54 years old in 2025.

What condition is SB I-35 over US 18 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 April 2024.

How much traffic does SB I-35 over US 18 carry?

About 8,400 vehicles per day (2022 count), of which roughly 33% are trucks.

How long is SB I-35 over US 18?

The structure is 275 ft (83.8 m) long with a longest span of 88 ft (26.8 m) and a deck 43 ft wide.

Who owns SB I-35 over US 18?

It is owned by the State Highway Agency.