US Bridges

FAU 6124/N.29th RD over I-39/US 51

Fair

LaSalle County, Illinois · 1.0 Mile S. of I-80 · Structure no. 050019400000000

Built
1985
40 years old
Condition
Fair
inspected February 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
296 ft
2 main spans
Daily traffic
375
2020 count
Owner
State
State Highway Agency

About this bridge

FAU 6124/N.29th RD over I-39/US 51 is a steel continuous stringer/multi-beam or girder carrying FAU 6124/N.29th RD over I-39/US 51 in LaSalle County, Illinois. It was built in 1985, so it is 40 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 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 375 vehicles a day, roughly 12% of them trucks, projected to reach 379 by 2046. The structure is 296 ft (90.2 m) long and 31 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesFAU 6124/N.29th RD
CrossesI-39/US 51
Location1.0 Mile S. of I-80
CountyLaSalle County
StateIllinois
Coordinates41.35366, -89.06189
Functional classUrban 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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionFebruary 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating65.4 US tons
Inventory rating39.2 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans2 (+2 approach)
Design loadHS 20
Structure length296 ft (90.2 m)
Longest span126 ft (38.4 m)
Deck width31 ft (9.5 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic375 (2020)
Projected traffic379 by 2046
Trucks12%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed3.1 mi (5 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 FAU 6124/N.29th RD over I-39/US 51 built?

It was built in 1985, making it 40 years old in 2025.

What condition is FAU 6124/N.29th RD 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 FAU 6124/N.29th RD over I-39/US 51 carry?

About 375 vehicles per day (2020 count), of which roughly 12% are trucks.

How long is FAU 6124/N.29th RD over I-39/US 51?

The structure is 296 ft (90.2 m) long with a longest span of 126 ft (38.4 m) and a deck 31 ft wide.

Who owns FAU 6124/N.29th RD over I-39/US 51?

It is owned by the State Highway Agency.