US Bridges

Il 177/160 over Kaskaskia Overflow

Fair

Washington County, Illinois · 3.7M W of Okawville · Structure no. 095007400000000

Built
1997
28 years old
Condition
Fair
inspected July 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
531 ft
6 main spans
Daily traffic
1,750
2023 count
Owner
State
State Highway Agency

About this bridge

Il 177/160 over Kaskaskia Overflow is a prestressed concrete stringer/multi-beam or girder carrying Il 177/160 over Kaskaskia Overflow in Washington County, Illinois. It was built in 1997, so it is 28 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 1,750 vehicles a day, roughly 10% of them trucks, projected to reach 2,299 by 2046. The structure is 531 ft (162 m) long and 35 ft wide. If it were closed, the detour would be 24.2 mi (39 km).

Location

Open in Google Maps
CarriesIl 177/160
CrossesKaskaskia Overflow
Location3.7M W of Okawville
RouteState Highway 160
CountyWashington County
StateIllinois
Coordinates38.44949, -89.62576
Functional classRural 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
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure8 Very GoodNo problems noted.
Channel and channel protection9 ExcellentNo problems noted.
Last inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating63.9 US tons
Inventory rating39.2 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans6
Design loadHS 20
Structure length531 ft (162 m)
Longest span88 ft (26.8 m)
Deck width35 ft (10.7 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,750 (2023)
Projected traffic2,299 by 2046
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed24.2 mi (39 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 Il 177/160 over Kaskaskia Overflow built?

It was built in 1997, making it 28 years old in 2025.

What condition is Il 177/160 over Kaskaskia Overflow 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 July 2024.

How much traffic does Il 177/160 over Kaskaskia Overflow carry?

About 1,750 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is Il 177/160 over Kaskaskia Overflow?

The structure is 531 ft (162 m) long with a longest span of 88 ft (26.8 m) and a deck 35 ft wide.

Who owns Il 177/160 over Kaskaskia Overflow?

It is owned by the State Highway Agency.