US Bridges

Ch 4 (500 N) over I-39/US 51

Fair

Marshall County, Illinois · 2.02 MI S 0F Ill 17 · Structure no. 062005300000000

Built
1989
36 years old
Condition
Fair
inspected March 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
229 ft
3 main spans
Daily traffic
650
2024 count
Owner
State
State Highway Agency

About this bridge

Ch 4 (500 N) over I-39/US 51 is a steel continuous stringer/multi-beam or girder carrying Ch 4 (500 N) over I-39/US 51 in Marshall County, Illinois. It was built in 1989, so it is 36 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 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 650 vehicles a day, roughly 17% of them trucks, projected to reach 732 by 2046. The structure is 229 ft (69.8 m) long and 37 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesCh 4 (500 N)
CrossesI-39/US 51
Location2.02 MI S 0F Ill 17
RouteCounty Highway 0
CountyMarshall County
StateIllinois
Coordinates40.9988, -89.05455
Functional classRural Major Collector

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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMarch 2023
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 rating75.4 US tons
Inventory rating45.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length229 ft (69.8 m)
Longest span166 ft (50.6 m)
Deck width37 ft (11.3 m)
Roadway width34 ft (10.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic650 (2024)
Projected traffic732 by 2046
Trucks17%
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—
NavigationNo navigation control on waterway

Frequently asked questions

When was Ch 4 (500 N) over I-39/US 51 built?

It was built in 1989, making it 36 years old in 2025.

What condition is Ch 4 (500 N) over I-39/US 51 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 March 2023.

How much traffic does Ch 4 (500 N) over I-39/US 51 carry?

About 650 vehicles per day (2024 count), of which roughly 17% are trucks.

How long is Ch 4 (500 N) over I-39/US 51?

The structure is 229 ft (69.8 m) long with a longest span of 166 ft (50.6 m) and a deck 37 ft wide.

Who owns Ch 4 (500 N) over I-39/US 51?

It is owned by the State Highway Agency.