US Bridges

FAP 320 (il 121) over South Fork Creek

Fair

Macon County, Illinois · 1.5 MI W of Heman · Structure no. 058012900000000

Built
1999
26 years old
Condition
Fair
inspected June 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete Continuous
Length
171 ft
2 main spans
Daily traffic
3,750
2023 count
Owner
State
State Highway Agency

About this bridge

FAP 320 (il 121) over South Fork Creek is a prestressed concrete continuous stringer/multi-beam or girder carrying FAP 320 (il 121) over South Fork Creek in Macon County, Illinois. It was built in 1999, so it is 26 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 3,750 vehicles a day, roughly 18% of them trucks, projected to reach 3,838 by 2046. The structure is 171 ft (52.2 m) long and 39 ft wide. If it were closed, the detour would be 16.8 mi (27 km).

Location

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CarriesFAP 320 (il 121)
CrossesSouth Fork Creek
Location1.5 MI W of Heman
RouteState Highway 121
CountyMacon County
StateIllinois
Coordinates39.95609, -89.13252
Functional classRural Principal Arterial - Other

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.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJune 2024
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation8: Equal to present desirable criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating66 US tons
Inventory rating40.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20 + Mod
Structure length171 ft (52.2 m)
Longest span86 ft (26.1 m)
Deck width39 ft (11.8 m)
Roadway width35 ft (10.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,750 (2023)
Projected traffic3,838 by 2046
Trucks18%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed16.8 mi (27 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—
NavigationNo navigation control on waterway

Frequently asked questions

When was FAP 320 (il 121) over South Fork Creek built?

It was built in 1999, making it 26 years old in 2025.

What condition is FAP 320 (il 121) over South Fork Creek 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 June 2024.

How much traffic does FAP 320 (il 121) over South Fork Creek carry?

About 3,750 vehicles per day (2023 count), of which roughly 18% are trucks.

How long is FAP 320 (il 121) over South Fork Creek?

The structure is 171 ft (52.2 m) long with a longest span of 86 ft (26.1 m) and a deck 39 ft wide.

Who owns FAP 320 (il 121) over South Fork Creek?

It is owned by the State Highway Agency.