US Bridges

TR 171 over Trib to Snakeden CR

Fair

Knox County, Illinois · NW-9-T11NR4E · Structure no. 048321800000000

Built
1976
49 years old
Condition
Fair
inspected February 2025
Type
Channel Beam
Concrete
Length
24 ft
1 main span
Daily traffic
50
2022 count
Owner
Town / Township
Town or Township Highway Agency

About this bridge

TR 171 over Trib to Snakeden CR is a concrete channel beam carrying TR 171 over Trib to Snakeden CR in Knox County, Illinois. It was built in 1976, so it is 49 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 5 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 24 ft (7.3 m) long and 23 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

Open in Google Maps
CarriesTR 171
CrossesTrib to Snakeden CR
LocationNW-9-T11NR4E
RouteCounty Highway 0
CountyKnox County
StateIllinois
Coordinates40.96059, -90.06084
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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionFebruary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment5: Somewhat better than minimum adequacy to tolerate being left in place as is
Operating rating48.9 US tons
Inventory rating35.7 US tons

Structure

Structure typeChannel Beam
MaterialConcrete
DeckConcrete, precast panels
Main spans1
Design loadHS 20
Structure length24 ft (7.3 m)
Longest span22 ft (6.7 m)
Deck width23 ft (7 m)
Roadway width20 ft (6.2 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 closed6.2 mi (10 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 171 over Trib to Snakeden CR built?

It was built in 1976, making it 49 years old in 2025.

What condition is TR 171 over Trib to Snakeden 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 February 2025.

How much traffic does TR 171 over Trib to Snakeden CR carry?

About 50 vehicles per day (2022 count).

How long is TR 171 over Trib to Snakeden CR?

The structure is 24 ft (7.3 m) long with a longest span of 22 ft (6.7 m) and a deck 23 ft wide.

Who owns TR 171 over Trib to Snakeden CR?

It is owned by the Town or Township Highway Agency.