US Bridges

TR 77 over Prairie CR

Fair

Iroquois County, Illinois · 3 MI E. of Ashkum · Structure no. 038323700000000

Built
1970
55 years old
Condition
Fair
inspected April 2023
Type
Slab
Concrete
Length
77 ft
3 main spans
Daily traffic
50
2022 count
Owner
Town / Township
Town or Township Highway Agency

About this bridge

TR 77 over Prairie CR is a concrete slab carrying TR 77 over Prairie CR in Iroquois County, Illinois. It was built in 1970, so it is 55 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 50 vehicles a day, projected to reach 51 by 2046. The structure is 77 ft (23.5 m) long and 26 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesTR 77
CrossesPrairie CR
Location3 MI E. of Ashkum
RouteCounty Highway 0
CountyIroquois County
StateIllinois
Coordinates40.87143, -87.9038
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 protection7 GoodSome minor problems.
Last inspectionApril 2023
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 geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating54.2 US tons
Inventory rating32.5 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 15
Structure length77 ft (23.5 m)
Longest span28 ft (8.5 m)
Deck width26 ft (8 m)
Roadway width24 ft (7.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic50 (2022)
Projected traffic51 by 2046
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 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 77 over Prairie CR built?

It was built in 1970, making it 55 years old in 2025.

What condition is TR 77 over Prairie CR 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 April 2023.

How much traffic does TR 77 over Prairie CR carry?

About 50 vehicles per day (2022 count).

How long is TR 77 over Prairie CR?

The structure is 77 ft (23.5 m) long with a longest span of 28 ft (8.5 m) and a deck 26 ft wide.

Who owns TR 77 over Prairie CR?

It is owned by the Town or Township Highway Agency.