US Bridges

FAI 255 NB over Harding Ditch South

Fair

St. Clair County, Illinois · 0.5 MI N ST Clair Av · Structure no. 082023900000000

Built
1982
43 years old
Condition
Fair
inspected January 2025
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
271 ft
3 main spans
Daily traffic
22,300
2023 count
Owner
State
State Highway Agency

About this bridge

FAI 255 NB over Harding Ditch South is a steel continuous stringer/multi-beam or girder carrying FAI 255 NB over Harding Ditch South in St. Clair County, Illinois. It was built in 1982, so it is 43 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 22,300 vehicles a day, roughly 16% of them trucks, projected to reach 24,139 by 2046. The structure is 271 ft (82.7 m) long and 59 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesFAI 255 NB
CrossesHarding Ditch South
Location0.5 MI N ST Clair Av
RouteInterstate 255
CountySt. Clair County
StateIllinois
Coordinates38.61281, -90.07501
Functional classUrban Principal Arterial - Interstate

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.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJanuary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating89.9 US tons
Inventory rating49.3 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length271 ft (82.7 m)
Longest span103 ft (31.5 m)
Deck width59 ft (18 m)
Roadway width56 ft (17.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic22,300 (2023)
Projected traffic24,139 by 2046
Trucks16%
Lanes on structure3
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

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 FAI 255 NB over Harding Ditch South built?

It was built in 1982, making it 43 years old in 2025.

What condition is FAI 255 NB over Harding Ditch South 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 January 2025.

How much traffic does FAI 255 NB over Harding Ditch South carry?

About 22,300 vehicles per day (2023 count), of which roughly 16% are trucks.

How long is FAI 255 NB over Harding Ditch South?

The structure is 271 ft (82.7 m) long with a longest span of 103 ft (31.5 m) and a deck 59 ft wide.

Who owns FAI 255 NB over Harding Ditch South?

It is owned by the State Highway Agency.