US Bridges

I-39/US 51 SB over Sandy Creek

Fair

LaSalle County, Illinois · 1.23 MI N of Ill 18 · Structure no. 050021200000000

Built
1988
37 years old
Condition
Fair
inspected February 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
152 ft
3 main spans
Daily traffic
9,700
2023 count
Owner
State
State Highway Agency

About this bridge

I-39/US 51 SB over Sandy Creek is a prestressed concrete stringer/multi-beam or girder carrying I-39/US 51 SB over Sandy Creek in LaSalle County, Illinois. It was built in 1988, so it is 37 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 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 9,700 vehicles a day, roughly 36% of them trucks, projected to reach 9,494 by 2046. The structure is 152 ft (46.3 m) long and 43 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
CrossesSandy Creek
Location1.23 MI N of Ill 18
RouteInterstate 39
CountyLaSalle County
StateIllinois
Coordinates41.13718, -89.07539
Functional classRural 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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionFebruary 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating106.5 US tons
Inventory rating59.6 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length152 ft (46.3 m)
Longest span50 ft (15.1 m)
Deck width43 ft (13.1 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic9,700 (2023)
Projected traffic9,494 by 2046
Trucks36%
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-39/US 51 SB over Sandy Creek built?

It was built in 1988, making it 37 years old in 2025.

What condition is I-39/US 51 SB over Sandy Creek 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 2023.

How much traffic does I-39/US 51 SB over Sandy Creek carry?

About 9,700 vehicles per day (2023 count), of which roughly 36% are trucks.

How long is I-39/US 51 SB over Sandy Creek?

The structure is 152 ft (46.3 m) long with a longest span of 50 ft (15.1 m) and a deck 43 ft wide.

Who owns I-39/US 51 SB over Sandy Creek?

It is owned by the State Highway Agency.