US Bridges

Il 105 (eb)(fap 74 over Lake Decatur

Good

Macon County, Illinois · In Decatur · Structure no. 058004700000000

Built
1970
55 years old, rebuilt 2023
Condition
Good
inspected December 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
369 ft
3 main spans
Daily traffic
7,800
2021 count
Owner
State
State Highway Agency

About this bridge

Il 105 (eb)(fap 74 over Lake Decatur is a steel continuous stringer/multi-beam or girder carrying Il 105 (eb)(fap 74 over Lake Decatur in Macon County, Illinois. It was built in 1970 and reconstructed in 2023, so it is 55 years old, older than the Illinois average of 45.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 7,800 vehicles a day, roughly 11% of them trucks, projected to reach 3,939 by 2046. The structure is 369 ft (112.5 m) long and 42 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesIl 105 (eb)(fap 74
CrossesLake Decatur
LocationIn Decatur
RouteState Highway 105
CountyMacon County
StateIllinois
Coordinates39.85229, -88.88334
Functional classUrban Minor Arterial

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck9 ExcellentNo problems noted.
Superstructure9 ExcellentNo problems noted.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionDecember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating46.4 US tons
Inventory rating35.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 25 or greater
Structure length369 ft (112.5 m)
Longest span133 ft (40.6 m)
Deck width42 ft (12.9 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic7,800 (2021)
Projected traffic3,939 by 2046
Trucks11%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$6.3 million
NavigationNo navigation control on waterway

Frequently asked questions

When was Il 105 (eb)(fap 74 over Lake Decatur built?

It was built in 1970, making it 55 years old in 2025. It was reconstructed in 2023.

What condition is Il 105 (eb)(fap 74 over Lake Decatur in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in December 2023.

How much traffic does Il 105 (eb)(fap 74 over Lake Decatur carry?

About 7,800 vehicles per day (2021 count), of which roughly 11% are trucks.

How long is Il 105 (eb)(fap 74 over Lake Decatur?

The structure is 369 ft (112.5 m) long with a longest span of 133 ft (40.6 m) and a deck 42 ft wide.

Who owns Il 105 (eb)(fap 74 over Lake Decatur?

It is owned by the State Highway Agency.