US Bridges

I-55/64 Cd WB "g" over Trendley Avenue

Fair

St. Clair County, Illinois · Pier G1 to Abut G14 · Structure no. 082025400000000

Built
1968
57 years old, rebuilt 1997
Condition
Fair
inspected December 2023
Type
Girder and Floorbeam System
Steel Continuous
Length
1,246 ft
13 main spans
Daily traffic
8,850
2024 count
Owner
State
State Highway Agency

About this bridge

I-55/64 Cd WB "g" over Trendley Avenue is a steel continuous girder and floorbeam system carrying I-55/64 Cd WB "g" over Trendley Avenue in St. Clair County, Illinois. It was built in 1968 and reconstructed in 1997, so it is 57 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 8,850 vehicles a day, roughly 15% of them trucks, projected to reach 23,230 by 2046. The structure is 1,246 ft (379.9 m) long and 36 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

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CarriesI-55/64 Cd WB "g"
CrossesTrendley Avenue
LocationPier G1 to Abut G14
CountySt. Clair County
StateIllinois
Coordinates38.61711, -90.16888
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
Deck7 GoodSome minor problems.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionDecember 2023
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 alignment6: Equal to present minimum criteria
Operating rating40.3 US tons
Inventory rating24.3 US tons

Structure

Structure typeGirder and Floorbeam System
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans13
Design loadHS 20
Structure length1,246 ft (379.9 m)
Longest span116 ft (35.4 m)
Deck width36 ft (11 m)
Roadway width33 ft (10 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic8,850 (2024)
Projected traffic23,230 by 2046
Trucks15%
Lanes on structure2
Traffic directionOne-way traffic
CarriesOverpass structure at an interchange
CrossesHighway
Detour if closed3.1 mi (5 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-55/64 Cd WB "g" over Trendley Avenue built?

It was built in 1968, making it 57 years old in 2025. It was reconstructed in 1997.

What condition is I-55/64 Cd WB "g" over Trendley Avenue 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 December 2023.

How much traffic does I-55/64 Cd WB "g" over Trendley Avenue carry?

About 8,850 vehicles per day (2024 count), of which roughly 15% are trucks.

How long is I-55/64 Cd WB "g" over Trendley Avenue?

The structure is 1,246 ft (379.9 m) long with a longest span of 116 ft (35.4 m) and a deck 36 ft wide.

Who owns I-55/64 Cd WB "g" over Trendley Avenue?

It is owned by the State Highway Agency.