US Bridges

Ill 251 (nb) over I 80

Fair

LaSalle County, Illinois · JCT Il 251 & I-80 · Structure no. 050007800000000

Built
1961
64 years old
Condition
Fair
inspected September 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
208 ft
4 main spans
Daily traffic
6,550
2023 count
Owner
State
State Highway Agency

About this bridge

Ill 251 (nb) over I 80 is a prestressed concrete stringer/multi-beam or girder carrying Ill 251 (nb) over I 80 in LaSalle County, Illinois. It was built in 1961, so it is 64 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 6,550 vehicles a day, roughly 9% of them trucks, projected to reach 6,919 by 2046. The structure is 208 ft (63.4 m) long and 36 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesIll 251 (nb)
CrossesI 80
LocationJCT Il 251 & I-80
RouteState Highway 251
CountyLaSalle County
StateIllinois
Coordinates41.36541, -89.12575
Functional classUrban Other Principal Arterial

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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionSeptember 2024
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 geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating98.2 US tons
Inventory rating55.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length208 ft (63.4 m)
Longest span61 ft (18.6 m)
Deck width36 ft (11 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic6,550 (2023)
Projected traffic6,919 by 2046
Trucks9%
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

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedOther structural work, including hydraulic replacements
Estimated improvement cost$180,000
NavigationNot applicable (no waterway)

Frequently asked questions

When was Ill 251 (nb) over I 80 built?

It was built in 1961, making it 64 years old in 2025.

What condition is Ill 251 (nb) over I 80 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 September 2024.

How much traffic does Ill 251 (nb) over I 80 carry?

About 6,550 vehicles per day (2023 count), of which roughly 9% are trucks.

How long is Ill 251 (nb) over I 80?

The structure is 208 ft (63.4 m) long with a longest span of 61 ft (18.6 m) and a deck 36 ft wide.

Who owns Ill 251 (nb) over I 80?

It is owned by the State Highway Agency.