US Bridges

County Highway 4 over Big Sister

Fair

Fulton County, Illinois · SW-5-T5NR4E · Structure no. 029500900000000

Built
1959
66 years old
Condition
Fair
inspected October 2023
Type
Culvert
Concrete
Length
27 ft
2 main spans
Daily traffic
75
2020 count
Owner
County
County Highway Agency

About this bridge

County Highway 4 over Big Sister is a concrete culvert carrying County Highway 4 over Big Sister in Fulton County, Illinois. It was built in 1959, so it is 66 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 75 vehicles a day, projected to reach 76 by 2046. The structure is 27 ft (8.3 m) long. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesCounty Highway 4
CrossesBig Sister
LocationSW-5-T5NR4E
RouteCounty Highway 0
CountyFulton County
StateIllinois
Coordinates40.43807, -90.08422
Functional classRural Minor Collector

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Channel and channel protection4 PoorAdvanced section loss, deterioration, spalling or scour.
Culvert5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: 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 rating44.6 US tons
Inventory rating26.8 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans2
Design loadHS 15
Structure length27 ft (8.3 m)
Longest span10 ft (3 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic75 (2020)
Projected traffic76 by 2046
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty 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 County Highway 4 over Big Sister built?

It was built in 1959, making it 66 years old in 2025.

What condition is County Highway 4 over Big Sister 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 October 2023.

How much traffic does County Highway 4 over Big Sister carry?

About 75 vehicles per day (2020 count).

How long is County Highway 4 over Big Sister?

The structure is 27 ft (8.3 m) long with a longest span of 10 ft (3 m).

Who owns County Highway 4 over Big Sister?

It is owned by the County Highway Agency.