US Bridges

Ill 166 over Stream

Fair

Williamson County, Illinois · 2.7 MI So of Ill 13 · Structure no. 100200800000000

Built
1934
91 years old
Condition
Fair
inspected October 2024
Type
Culvert
Concrete Continuous
Length
32 ft
2 main spans
Daily traffic
3,000
2023 count
Owner
State
State Highway Agency

About this bridge

Ill 166 over Stream is a concrete continuous culvert carrying Ill 166 over Stream in Williamson County, Illinois. It was built in 1934, so it is 91 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 3,000 vehicles a day, roughly 6% of them trucks, projected to reach 2,677 by 2046. The structure is 32 ft (9.8 m) long. If it were closed, the detour would be 26.7 mi (43 km).

Location

Open in Google Maps
CarriesIll 166
CrossesStream
Location2.7 MI So of Ill 13
RouteState Highway 166
CountyWilliamson County
StateIllinois
Coordinates37.68944, -88.85561
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
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating57.5 US tons
Inventory rating34.3 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans2
Design loadUnknown
Structure length32 ft (9.8 m)
Longest span14 ft (4.3 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,000 (2023)
Projected traffic2,677 by 2046
Trucks6%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed26.7 mi (43 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 166 over Stream built?

It was built in 1934, making it 91 years old in 2025.

What condition is Ill 166 over Stream 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 October 2024.

How much traffic does Ill 166 over Stream carry?

About 3,000 vehicles per day (2023 count), of which roughly 6% are trucks.

How long is Ill 166 over Stream?

The structure is 32 ft (9.8 m) long with a longest span of 14 ft (4.3 m).

Who owns Ill 166 over Stream?

It is owned by the State Highway Agency.