US Bridges

I-255 NB Mainline over I-270

Fair

Madison County, Illinois · 1.9 MI W of Il 157 · Structure no. 060024200000000

Built
1994
31 years old
Condition
Fair
inspected November 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
333 ft
3 main spans
Daily traffic
20,250
2023 count
Owner
State
State Highway Agency

About this bridge

I-255 NB Mainline over I-270 is a steel continuous stringer/multi-beam or girder carrying I-255 NB Mainline over I-270 in Madison County, Illinois. It was built in 1994, so it is 31 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 20,250 vehicles a day, roughly 10% of them trucks, projected to reach 21,935 by 2046. The structure is 333 ft (101.5 m) long and 68 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesI-255 NB Mainline
CrossesI-270
Location1.9 MI W of Il 157
RouteInterstate 255
CountyMadison County
StateIllinois
Coordinates38.75612, -90.04354
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure8 Very GoodNo problems noted.
Last inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating67.9 US tons
Inventory rating40.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3 (+2 approach)
Design loadHS 20 + Mod
Structure length333 ft (101.5 m)
Longest span109 ft (33.1 m)
Deck width68 ft (20.6 m)
Roadway width64 ft (19.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic20,250 (2023)
Projected traffic21,935 by 2046
Trucks10%
Lanes on structure4
Traffic directionOne-way traffic
CarriesOverpass structure at an interchange
CrossesHighway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkNon-Interstate 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-255 NB Mainline over I-270 built?

It was built in 1994, making it 31 years old in 2025.

What condition is I-255 NB Mainline over I-270 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 November 2024.

How much traffic does I-255 NB Mainline over I-270 carry?

About 20,250 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is I-255 NB Mainline over I-270?

The structure is 333 ft (101.5 m) long with a longest span of 109 ft (33.1 m) and a deck 68 ft wide.

Who owns I-255 NB Mainline over I-270?

It is owned by the State Highway Agency.