US Bridges

I-55 SB over Salt Creek

Fair

Logan County, Illinois · 2.1M S IL10 · Structure no. 054004100000000

Built
1973
52 years old
Condition
Fair
inspected September 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
675 ft
7 main spans
Daily traffic
13,750
2023 count
Owner
State
State Highway Agency

About this bridge

I-55 SB over Salt Creek is a steel continuous stringer/multi-beam or girder carrying I-55 SB over Salt Creek in Logan County, Illinois. It was built in 1973, so it is 52 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 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 13,750 vehicles a day, roughly 32% of them trucks, projected to reach 13,230 by 2046. The structure is 675 ft (205.6 m) long and 58 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI-55 SB
CrossesSalt Creek
Location2.1M S IL10
RouteInterstate 55
CountyLogan County
StateIllinois
Coordinates40.12752, -89.41665
Functional classRural 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 protection7 GoodSome minor problems.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourCountermeasures installed to correct a previously existing problem
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 rating78.9 US tons
Inventory rating42.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans7
Design loadHS 20 + Mod
Structure length675 ft (205.6 m)
Longest span150 ft (45.7 m)
Deck width58 ft (17.7 m)
Roadway width54 ft (16.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic13,750 (2023)
Projected traffic13,230 by 2046
Trucks32%
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 I-55 SB over Salt Creek built?

It was built in 1973, making it 52 years old in 2025.

What condition is I-55 SB over Salt 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 September 2023.

How much traffic does I-55 SB over Salt Creek carry?

About 13,750 vehicles per day (2023 count), of which roughly 32% are trucks.

How long is I-55 SB over Salt Creek?

The structure is 675 ft (205.6 m) long with a longest span of 150 ft (45.7 m) and a deck 58 ft wide.

Who owns I-55 SB over Salt Creek?

It is owned by the State Highway Agency.