US Bridges

Il 173 over Piscasaw Creektrib.

Good

Boone County, Illinois · At Mchenry Co. Ln. · Structure no. 004001800000000

Built
2001
24 years old
Condition
Good
inspected April 2022
Type
Slab
Concrete Continuous
Length
90 ft
3 main spans
Daily traffic
5,000
2023 count
Owner
State
State Highway Agency

About this bridge

Il 173 over Piscasaw Creektrib. is a concrete continuous slab carrying Il 173 over Piscasaw Creektrib. in Boone County, Illinois. It was built in 2001, so it is 24 years old, younger than the Illinois average of 45.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 5,000 vehicles a day, roughly 11% of them trucks, projected to reach 5,408 by 2046. The structure is 90 ft (27.4 m) long and 39 ft wide. If it were closed, the detour would be 19.9 mi (32 km).

Location

Open in Google Maps
CarriesIl 173
CrossesPiscasaw Creektrib.
LocationAt Mchenry Co. Ln.
RouteState Highway 173
CountyBoone County
StateIllinois
Coordinates42.40069, -88.70622
Functional classRural Principal Arterial - Other

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionApril 2022
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than 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 rating83.2 US tons
Inventory rating50 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length90 ft (27.4 m)
Longest span35 ft (10.7 m)
Deck width39 ft (11.8 m)
Roadway width35 ft (10.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic5,000 (2023)
Projected traffic5,408 by 2046
Trucks11%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed19.9 mi (32 km)
TollOn a free road
National Highway SystemYes

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 173 over Piscasaw Creektrib. built?

It was built in 2001, making it 24 years old in 2025.

What condition is Il 173 over Piscasaw Creektrib. in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in April 2022.

How much traffic does Il 173 over Piscasaw Creektrib. carry?

About 5,000 vehicles per day (2023 count), of which roughly 11% are trucks.

How long is Il 173 over Piscasaw Creektrib.?

The structure is 90 ft (27.4 m) long with a longest span of 35 ft (10.7 m) and a deck 39 ft wide.

Who owns Il 173 over Piscasaw Creektrib.?

It is owned by the State Highway Agency.