US Bridges

Ill 3 over Cahokia Canal

Fair

St. Clair County, Illinois · 0.3 M N National Cty · Structure no. 082201000000000

Built
1935
90 years old
Condition
Fair
inspected September 2023
Type
Culvert
Concrete Continuous
Length
48 ft
3 main spans
Daily traffic
4,600
2023 count
Owner
State
State Highway Agency

About this bridge

Ill 3 over Cahokia Canal is a concrete continuous culvert carrying Ill 3 over Cahokia Canal in St. Clair County, Illinois. It was built in 1935, so it is 90 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 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 4,600 vehicles a day, roughly 18% of them trucks, projected to reach 4,899 by 2046. The structure is 48 ft (14.5 m) long. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesIll 3
CrossesCahokia Canal
Location0.3 M N National Cty
RouteState Highway 3
CountySt. Clair County
StateIllinois
Coordinates38.64379, -90.15921
Functional classUrban Minor 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
Channel and channel protection7 GoodSome minor problems.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating91.4 US tons
Inventory rating54.7 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans3
Design loadUnknown
Structure length48 ft (14.5 m)
Longest span14 ft (4.2 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,600 (2023)
Projected traffic4,899 by 2046
Trucks18%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemNo

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 Ill 3 over Cahokia Canal built?

It was built in 1935, making it 90 years old in 2025.

What condition is Ill 3 over Cahokia Canal 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 2023.

How much traffic does Ill 3 over Cahokia Canal carry?

About 4,600 vehicles per day (2023 count), of which roughly 18% are trucks.

How long is Ill 3 over Cahokia Canal?

The structure is 48 ft (14.5 m) long with a longest span of 14 ft (4.2 m).

Who owns Ill 3 over Cahokia Canal?

It is owned by the State Highway Agency.