US Bridges

Il 177/160 over Queens Lake Slough

Fair

Clinton County, Illinois · 1 MI E New Memphis · Structure no. 014007300000000

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

About this bridge

Il 177/160 over Queens Lake Slough is a prestressed concrete stringer/multi-beam or girder carrying Il 177/160 over Queens Lake Slough in Clinton 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 2,090 by 2046. The structure is 481 ft (146.5 m) long and 35 ft wide. If it were closed, the detour would be 60.3 mi (97 km).

Location

Open in Google Maps
CarriesIl 177/160
CrossesQueens Lake Slough
Location1 MI E New Memphis
RouteState Highway 160
CountyClinton County
StateIllinois
Coordinates38.45876, -89.65846
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 protection8 Very GoodNo problems noted.
Last inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
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 rating65.4 US tons
Inventory rating41.1 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans5
Design loadHS 20
Structure length481 ft (146.5 m)
Longest span105 ft (32.1 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 traffic2,090 by 2046
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed60.3 mi (97 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 Queens Lake Slough built?

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

What condition is Il 177/160 over Queens Lake Slough 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 Queens Lake Slough carry?

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

How long is Il 177/160 over Queens Lake Slough?

The structure is 481 ft (146.5 m) long with a longest span of 105 ft (32.1 m) and a deck 35 ft wide.

Who owns Il 177/160 over Queens Lake Slough?

It is owned by the State Highway Agency.