US Bridges

County Highway 30 over Over-Flow Lake Story

Fair

Knox County, Illinois · N1/2-32-T12NR1E · Structure no. 048500600000000

Built
1928
97 years old
Condition
Fair
inspected February 2024
Type
Culvert
Concrete
Length
33 ft
3 main spans
Daily traffic
375
2022 count
Owner
County
County Highway Agency

About this bridge

County Highway 30 over Over-Flow Lake Story is a concrete culvert carrying County Highway 30 over Over-Flow Lake Story in Knox County, Illinois. It was built in 1928, so it is 97 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 375 vehicles a day, roughly 5% of them trucks, projected to reach 480 by 2046. The structure is 33 ft (10.1 m) long. If it were closed, the detour would be 3.1 mi (5 km).

Location

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CarriesCounty Highway 30
CrossesOver-Flow Lake Story
LocationN1/2-32-T12NR1E
CountyKnox County
StateIllinois
Coordinates40.9891, -90.41155
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 protection7 GoodSome minor problems.
Culvert5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionFebruary 2024
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
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating31.4 US tons
Inventory rating18.5 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans3
Design loadUnknown
Structure length33 ft (10.1 m)
Longest span11 ft (3.4 m)
Deck width0 ft (0 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic375 (2022)
Projected traffic480 by 2046
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 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 30 over Over-Flow Lake Story built?

It was built in 1928, making it 97 years old in 2025.

What condition is County Highway 30 over Over-Flow Lake Story 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 February 2024.

How much traffic does County Highway 30 over Over-Flow Lake Story carry?

About 375 vehicles per day (2022 count), of which roughly 5% are trucks.

How long is County Highway 30 over Over-Flow Lake Story?

The structure is 33 ft (10.1 m) long with a longest span of 11 ft (3.4 m).

Who owns County Highway 30 over Over-Flow Lake Story?

It is owned by the County Highway Agency.