US Bridges

FAU 6431/CH 29 over I-55

Fair

McLean County, Illinois · .5 MI N of Towanda · Structure no. 057016200000000

Built
1974
51 years old
Condition
Fair
inspected May 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
295 ft
2 main spans
Daily traffic
3,300
2024 count
Owner
State
State Highway Agency

About this bridge

FAU 6431/CH 29 over I-55 is a steel continuous stringer/multi-beam or girder carrying FAU 6431/CH 29 over I-55 in McLean County, Illinois. It was built in 1974, so it is 51 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 3,300 vehicles a day, roughly 13% of them trucks, projected to reach 3,687 by 2046. The structure is 295 ft (89.9 m) long and 68 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

Location

Open in Google Maps
CarriesFAU 6431/CH 29
CrossesI-55
Location.5 MI N of Towanda
CountyMcLean County
StateIllinois
Coordinates40.57169, -88.90089
Functional classUrban Minor 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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionMay 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 geometry9: Superior to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating62.2 US tons
Inventory rating36.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans2 (+2 approach)
Design loadHS 20
Structure length295 ft (89.9 m)
Longest span117 ft (35.7 m)
Deck width68 ft (20.7 m)
Roadway width47 ft (14.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,300 (2024)
Projected traffic3,687 by 2046
Trucks13%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesOverpass structure at an interchange
CrossesHighway
Detour if closed8.1 mi (13 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 FAU 6431/CH 29 over I-55 built?

It was built in 1974, making it 51 years old in 2025.

What condition is FAU 6431/CH 29 over I-55 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 May 2023.

How much traffic does FAU 6431/CH 29 over I-55 carry?

About 3,300 vehicles per day (2024 count), of which roughly 13% are trucks.

How long is FAU 6431/CH 29 over I-55?

The structure is 295 ft (89.9 m) long with a longest span of 117 ft (35.7 m) and a deck 68 ft wide.

Who owns FAU 6431/CH 29 over I-55?

It is owned by the State Highway Agency.