US Bridges

I-55 (nb)/ I-72 (e over Il 29 / So Grand Ave

Good

Sangamon County, Illinois · I-55/IL 29 Int E Spi · Structure no. 084001100000000

Built
1963
62 years old, rebuilt 1995
Condition
Good
inspected April 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
255 ft
4 main spans
Daily traffic
25,400
2023 count
Owner
State
State Highway Agency

About this bridge

I-55 (nb)/ I-72 (e over Il 29 / So Grand Ave is a steel continuous stringer/multi-beam or girder carrying I-55 (nb)/ I-72 (e over Il 29 / So Grand Ave in Sangamon County, Illinois. It was built in 1963 and reconstructed in 1995, so it is 62 years old, older 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 25,400 vehicles a day, roughly 24% of them trucks, projected to reach 26,412 by 2046. The structure is 255 ft (77.8 m) long and 70 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

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CarriesI-55 (nb)/ I-72 (e
CrossesIl 29 / So Grand Ave
LocationI-55/IL 29 Int E Spi
RouteInterstate 55
CountySangamon County
StateIllinois
Coordinates39.78568, -89.59938
Functional classUrban 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.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating78.9 US tons
Inventory rating42.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20 + Mod
Structure length255 ft (77.8 m)
Longest span80 ft (24.4 m)
Deck width70 ft (21.2 m)
Roadway width66 ft (20.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic25,400 (2023)
Projected traffic26,412 by 2046
Trucks24%
Lanes on structure2
Traffic directionOne-way traffic
CarriesOverpass structure at an interchange
CrossesHighway
Detour if closed1.9 mi (3 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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was I-55 (nb)/ I-72 (e over Il 29 / So Grand Ave built?

It was built in 1963, making it 62 years old in 2025. It was reconstructed in 1995.

What condition is I-55 (nb)/ I-72 (e over Il 29 / So Grand Ave 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 April 2024.

How much traffic does I-55 (nb)/ I-72 (e over Il 29 / So Grand Ave carry?

About 25,400 vehicles per day (2023 count), of which roughly 24% are trucks.

How long is I-55 (nb)/ I-72 (e over Il 29 / So Grand Ave?

The structure is 255 ft (77.8 m) long with a longest span of 80 ft (24.4 m) and a deck 70 ft wide.

Who owns I-55 (nb)/ I-72 (e over Il 29 / So Grand Ave?

It is owned by the State Highway Agency.