US Bridges

I-155SB to 55NB Ra over I-155 NB & I-55 SB

Fair

Logan County, Illinois · I-55/155 NW Lincoln · Structure no. 054005100000000

Built
1973
52 years old
Condition
Fair
inspected February 2025
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
250 ft
3 main spans
Daily traffic
50
2022 count
Owner
State
State Highway Agency

About this bridge

I-155SB to 55NB Ra over I-155 NB & I-55 SB is a steel continuous stringer/multi-beam or girder carrying I-155SB to 55NB Ra over I-155 NB & I-55 SB in Logan County, Illinois. It was built in 1973, so it is 52 years old, older 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 50 vehicles a day, roughly 20% of them trucks, projected to reach 53 by 2046. The structure is 250 ft (76.1 m) long and 28 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesI-155SB to 55NB Ra
CrossesI-155 NB & I-55 SB
LocationI-55/155 NW Lincoln
CountyLogan County
StateIllinois
Coordinates40.17853, -89.41643
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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
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 alignment6: Equal to present minimum criteria
Operating rating83.2 US tons
Inventory rating50 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20 + Mod
Structure length250 ft (76.1 m)
Longest span94 ft (28.7 m)
Deck width28 ft (8.5 m)
Roadway width25 ft (7.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic50 (2022)
Projected traffic53 by 2046
Trucks20%
Lanes on structure1
Traffic directionOne-way traffic
CarriesThird level (interchange)
CrossesHighway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

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-155SB to 55NB Ra over I-155 NB & I-55 SB built?

It was built in 1973, making it 52 years old in 2025.

What condition is I-155SB to 55NB Ra over I-155 NB & I-55 SB 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-155SB to 55NB Ra over I-155 NB & I-55 SB carry?

About 50 vehicles per day (2022 count), of which roughly 20% are trucks.

How long is I-155SB to 55NB Ra over I-155 NB & I-55 SB?

The structure is 250 ft (76.1 m) long with a longest span of 94 ft (28.7 m) and a deck 28 ft wide.

Who owns I-155SB to 55NB Ra over I-155 NB & I-55 SB?

It is owned by the State Highway Agency.