US Bridges

I-39 NB over Harrison Ave

Poor

Winnebago County, Illinois · .6 MI S of I-90 · Structure no. 101007100000000

Built
1963
62 years old
Condition
Poor
inspected January 2025
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
228 ft
4 main spans
Daily traffic
21,150
2023 count
Owner
State
State Highway Agency

About this bridge

I-39 NB over Harrison Ave is a steel continuous stringer/multi-beam or girder carrying I-39 NB over Harrison Ave in Winnebago County, Illinois. It was built in 1963, so it is 62 years old, older than the Illinois average of 45.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 21,150 vehicles a day, roughly 29% of them trucks, projected to reach 22,473 by 2046. The structure is 228 ft (69.5 m) long and 53 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesI-39 NB
CrossesHarrison Ave
Location.6 MI S of I-90
RouteInterstate 39
CountyWinnebago County
StateIllinois
Coordinates42.23933, -88.96574
Functional classUrban Principal Arterial - Interstate

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionJanuary 2025
Inspection intervalevery 12 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating63.2 US tons
Inventory rating32.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20 + Mod
Structure length228 ft (69.5 m)
Longest span68 ft (20.7 m)
Deck width53 ft (16.1 m)
Roadway width50 ft (15.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic21,150 (2023)
Projected traffic22,473 by 2046
Trucks29%
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 I-39 NB over Harrison Ave built?

It was built in 1963, making it 62 years old in 2025.

What condition is I-39 NB over Harrison Ave in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in January 2025.

How much traffic does I-39 NB over Harrison Ave carry?

About 21,150 vehicles per day (2023 count), of which roughly 29% are trucks.

How long is I-39 NB over Harrison Ave?

The structure is 228 ft (69.5 m) long with a longest span of 68 ft (20.7 m) and a deck 53 ft wide.

Who owns I-39 NB over Harrison Ave?

It is owned by the State Highway Agency.