US Bridges

Ill 138 over Cahokia Creek

Fair

Macoupin County, Illinois · 1.9MI W JCT FAI 55 · Structure no. 059005400000000

Built
1992
33 years old
Condition
Fair
inspected September 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
126 ft
3 main spans
Daily traffic
2,700
2023 count
Owner
State
State Highway Agency

About this bridge

Ill 138 over Cahokia Creek is a steel continuous stringer/multi-beam or girder carrying Ill 138 over Cahokia Creek in Macoupin County, Illinois. It was built in 1992, so it is 33 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 2,700 vehicles a day, roughly 7% of them trucks, projected to reach 3,131 by 2046. The structure is 126 ft (38.4 m) long and 35 ft wide. If it were closed, the detour would be 14.3 mi (23 km).

Location

Open in Google Maps
CarriesIll 138
CrossesCahokia Creek
Location1.9MI W JCT FAI 55
RouteState Highway 138
CountyMacoupin County
StateIllinois
Coordinates39.07884, -89.78197
Functional classRural Major Collector

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.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
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
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating98.2 US tons
Inventory rating71.1 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length126 ft (38.4 m)
Longest span45 ft (13.7 m)
Deck width35 ft (10.7 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,700 (2023)
Projected traffic3,131 by 2046
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed14.3 mi (23 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 138 over Cahokia Creek built?

It was built in 1992, making it 33 years old in 2025.

What condition is Ill 138 over Cahokia Creek 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 138 over Cahokia Creek carry?

About 2,700 vehicles per day (2023 count), of which roughly 7% are trucks.

How long is Ill 138 over Cahokia Creek?

The structure is 126 ft (38.4 m) long with a longest span of 45 ft (13.7 m) and a deck 35 ft wide.

Who owns Ill 138 over Cahokia Creek?

It is owned by the State Highway Agency.