US Bridges

I-39 & US 51 SB over U.P. RR

Fair

Ogle County, Illinois · 0.65 MI S of Ill 38 · Structure no. 071005900000000

Built
1981
44 years old
Condition
Fair
inspected February 2025
Type
Stringer/Multi-beam or Girder
Prestressed Concrete Continuous
Length
232 ft
4 main spans
Daily traffic
14,550
2023 count
Owner
State
State Highway Agency

About this bridge

I-39 & US 51 SB over U.P. RR is a prestressed concrete continuous stringer/multi-beam or girder carrying I-39 & US 51 SB over U.P. RR in Ogle County, Illinois. It was built in 1981, so it is 44 years old, younger than the Illinois average of 45.3 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 14,550 vehicles a day, roughly 37% of them trucks, projected to reach 15,392 by 2046. The structure is 232 ft (70.7 m) long and 42 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesI-39 & US 51 SB
CrossesU.P. RR
Location0.65 MI S of Ill 38
RouteInterstate 39
CountyOgle County
StateIllinois
Coordinates41.92451, -89.0238
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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionFebruary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating57.1 US tons
Inventory rating35.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20 + Mod
Structure length232 ft (70.7 m)
Longest span61 ft (18.6 m)
Deck width42 ft (12.8 m)
Roadway width38 ft (11.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic14,550 (2023)
Projected traffic15,392 by 2046
Trucks37%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesRailroad
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-39 & US 51 SB over U.P. RR built?

It was built in 1981, making it 44 years old in 2025.

What condition is I-39 & US 51 SB over U.P. RR 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 February 2025.

How much traffic does I-39 & US 51 SB over U.P. RR carry?

About 14,550 vehicles per day (2023 count), of which roughly 37% are trucks.

How long is I-39 & US 51 SB over U.P. RR?

The structure is 232 ft (70.7 m) long with a longest span of 61 ft (18.6 m) and a deck 42 ft wide.

Who owns I-39 & US 51 SB over U.P. RR?

It is owned by the State Highway Agency.