US Bridges

I-39/US 51 NB over Trib Six Mile Creek

Good

McLean County, Illinois · 3.7 MI N of I-55 · Structure no. 057021100000000

Built
1989
36 years old
Condition
Good
inspected May 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
71 ft
1 main span
Daily traffic
8,650
2023 count
Owner
State
State Highway Agency

About this bridge

I-39/US 51 NB over Trib Six Mile Creek is a prestressed concrete stringer/multi-beam or girder carrying I-39/US 51 NB over Trib Six Mile Creek in McLean County, Illinois. It was built in 1989, so it is 36 years old, younger than the Illinois average of 45.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 8,650 vehicles a day, roughly 37% of them trucks, projected to reach 9,343 by 2046. The structure is 71 ft (21.5 m) long and 43 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesI-39/US 51 NB
CrossesTrib Six Mile Creek
Location3.7 MI N of I-55
RouteInterstate 39
Coordinates40.59239, -89.00263
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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than 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 rating53.6 US tons
Inventory rating37.5 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length71 ft (21.5 m)
Longest span68 ft (20.7 m)
Deck width43 ft (13.2 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic8,650 (2023)
Projected traffic9,343 by 2046
Trucks37%
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 NB over Trib Six Mile Creek built?

It was built in 1989, making it 36 years old in 2025.

What condition is I-39/US 51 NB over Trib Six Mile Creek 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 May 2023.

How much traffic does I-39/US 51 NB over Trib Six Mile Creek carry?

About 8,650 vehicles per day (2023 count), of which roughly 37% are trucks.

How long is I-39/US 51 NB over Trib Six Mile Creek?

The structure is 71 ft (21.5 m) long with a longest span of 68 ft (20.7 m) and a deck 43 ft wide.

Who owns I-39/US 51 NB over Trib Six Mile Creek?

It is owned by the State Highway Agency.