US Bridges

FAP 322(NB)(US 51) over IL-48 & NS RR

Fair

Macon County, Illinois · .5 MI SW of Decatur · Structure no. 058010900000000

Built
1978
47 years old
Condition
Fair
inspected May 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
275 ft
4 main spans
Daily traffic
5,900
2023 count
Owner
State
State Highway Agency

About this bridge

FAP 322(NB)(US 51) over IL-48 & NS RR is a steel continuous stringer/multi-beam or girder carrying FAP 322(NB)(US 51) over IL-48 & NS RR in Macon County, Illinois. It was built in 1978, so it is 47 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 5,900 vehicles a day, roughly 25% of them trucks, projected to reach 2,727 by 2046. The structure is 275 ft (83.9 m) long and 50 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesFAP 322(NB)(US 51)
CrossesIL-48 & NS RR
Location.5 MI SW of Decatur
RouteU.S. Route 51
CountyMacon County
StateIllinois
Coordinates39.80002, -89.00837
Functional classUrban Principal Arterial - Other Freeway or Expressway

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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionMay 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 alignment8: Equal to present desirable criteria
Operating rating72.1 US tons
Inventory rating41.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length275 ft (83.9 m)
Longest span123 ft (37.4 m)
Deck width50 ft (15.2 m)
Roadway width46 ft (14 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic5,900 (2023)
Projected traffic2,727 by 2046
Trucks25%
Lanes on structure2
Traffic directionOne-way traffic
CarriesOverpass structure at an interchange
CrossesHighway and railroad
Detour if closed1.2 mi (2 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 FAP 322(NB)(US 51) over IL-48 & NS RR built?

It was built in 1978, making it 47 years old in 2025.

What condition is FAP 322(NB)(US 51) over IL-48 & NS RR 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 2024.

How much traffic does FAP 322(NB)(US 51) over IL-48 & NS RR carry?

About 5,900 vehicles per day (2023 count), of which roughly 25% are trucks.

How long is FAP 322(NB)(US 51) over IL-48 & NS RR?

The structure is 275 ft (83.9 m) long with a longest span of 123 ft (37.4 m) and a deck 50 ft wide.

Who owns FAP 322(NB)(US 51) over IL-48 & NS RR?

It is owned by the State Highway Agency.