US Bridges

TR 320 over Crooked Leg Creek

Fair

LaSalle County, Illinois · E 18th at N3605 · Structure no. 050356400000000

Built
2000
25 years old
Condition
Fair
inspected July 2024
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
71 ft
1 main span
Daily traffic
175
2020 count
Owner
Town / Township
Town or Township Highway Agency

About this bridge

TR 320 over Crooked Leg Creek is a prestressed concrete box beam or girders - multiple carrying TR 320 over Crooked Leg Creek in LaSalle County, Illinois. It was built in 2000, so it is 25 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 175 vehicles a day, roughly 5% of them trucks, projected to reach 177 by 2046. The structure is 71 ft (21.6 m) long and 24 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesTR 320
CrossesCrooked Leg Creek
LocationE 18th at N3605
RouteCounty Highway 0
CountyLaSalle County
StateIllinois
Coordinates41.45747, -88.81477
Functional classRural Local

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
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 rating48.6 US tons
Inventory rating35.7 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans1
Design loadHS 20
Structure length71 ft (21.6 m)
Longest span68 ft (20.8 m)
Deck width24 ft (7.3 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic175 (2020)
Projected traffic177 by 2046
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerTown or Township Highway Agency
Maintained byTown or Township 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 TR 320 over Crooked Leg Creek built?

It was built in 2000, making it 25 years old in 2025.

What condition is TR 320 over Crooked Leg 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 July 2024.

How much traffic does TR 320 over Crooked Leg Creek carry?

About 175 vehicles per day (2020 count), of which roughly 5% are trucks.

How long is TR 320 over Crooked Leg Creek?

The structure is 71 ft (21.6 m) long with a longest span of 68 ft (20.8 m) and a deck 24 ft wide.

Who owns TR 320 over Crooked Leg Creek?

It is owned by the Town or Township Highway Agency.