US Bridges

US 6 FAP 623 over I-39/US 51

Fair

LaSalle County, Illinois · 1.3 MI E of Ill 351 · Structure no. 050019500000000

Built
1986
39 years old
Condition
Fair
inspected February 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
407 ft
2 main spans
Daily traffic
9,050
2023 count
Owner
State
State Highway Agency

About this bridge

US 6 FAP 623 over I-39/US 51 is a steel continuous stringer/multi-beam or girder carrying US 6 FAP 623 over I-39/US 51 in LaSalle County, Illinois. It was built in 1986, so it is 39 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 9,050 vehicles a day, roughly 16% of them trucks, projected to reach 9,949 by 2046. The structure is 407 ft (124.1 m) long and 69 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesUS 6 FAP 623
CrossesI-39/US 51
Location1.3 MI E of Ill 351
RouteU.S. Route 6
CountyLaSalle County
StateIllinois
Coordinates41.33649, -89.07144
Functional classUrban Other Principal Arterial

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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionFebruary 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 geometry9: Superior to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating75 US tons
Inventory rating44.6 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans2 (+2 approach)
Design loadHS 20
Structure length407 ft (124.1 m)
Longest span152 ft (46.3 m)
Deck width69 ft (21.1 m)
Roadway width66 ft (20.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic9,050 (2023)
Projected traffic9,949 by 2046
Trucks16%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesOverpass structure at an interchange
CrossesHighway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemYes

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 US 6 FAP 623 over I-39/US 51 built?

It was built in 1986, making it 39 years old in 2025.

What condition is US 6 FAP 623 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 February 2024.

How much traffic does US 6 FAP 623 over I-39/US 51 carry?

About 9,050 vehicles per day (2023 count), of which roughly 16% are trucks.

How long is US 6 FAP 623 over I-39/US 51?

The structure is 407 ft (124.1 m) long with a longest span of 152 ft (46.3 m) and a deck 69 ft wide.

Who owns US 6 FAP 623 over I-39/US 51?

It is owned by the State Highway Agency.