US Bridges

TR 399-100N over I-74

Fair

Knox County, Illinois · 1 MI SW of Woodhull · Structure no. 037010500000000

Built
1965
60 years old
Condition
Fair
inspected November 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
223 ft
4 main spans
Daily traffic
75
2010 count
Owner
State
State Highway Agency

About this bridge

TR 399-100N over I-74 is a steel continuous stringer/multi-beam or girder carrying TR 399-100N over I-74 in Knox County, Illinois. It was built in 1965, so it is 60 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 75 vehicles a day, roughly 13% of them trucks, projected to reach 81 by 2046. The structure is 223 ft (68 m) long and 30 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesTR 399-100N
CrossesI-74
Location1 MI SW of Woodhull
RouteCounty Highway 0
CountyKnox County
StateIllinois
Coordinates41.1657, -90.33278
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Last inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating60.7 US tons
Inventory rating35.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 15
Structure length223 ft (68 m)
Longest span67 ft (20.4 m)
Deck width30 ft (9.1 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic75 (2010)
Projected traffic81 by 2046
Trucks13%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed3.7 mi (6 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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was TR 399-100N over I-74 built?

It was built in 1965, making it 60 years old in 2025.

What condition is TR 399-100N over I-74 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 November 2024.

How much traffic does TR 399-100N over I-74 carry?

About 75 vehicles per day (2010 count), of which roughly 13% are trucks.

How long is TR 399-100N over I-74?

The structure is 223 ft (68 m) long with a longest span of 67 ft (20.4 m) and a deck 30 ft wide.

Who owns TR 399-100N over I-74?

It is owned by the State Highway Agency.