US Bridges

KY-18 over I-75

Fair

Boone County, Kentucky · 1 MI W of JCT US 25 · Structure no. 008B00009N

Built
1960
65 years old
Condition
Fair
inspected June 2023
Type
Tee Beam
Concrete Continuous
Length
276 ft
4 main spans
Daily traffic
53,570
2023 count
Owner
State
State Highway Agency

About this bridge

KY-18 over I-75 is a concrete continuous tee beam carrying KY-18 over I-75 in Boone County, Kentucky. It was built in 1960, so it is 65 years old, older than the Kentucky average of 46.6 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 53,570 vehicles a day, roughly 14% of them trucks, projected to reach 53,570 by 2043. The structure is 276 ft (84.1 m) long and 90 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesKY-18
CrossesI-75
Location1 MI W of JCT US 25
RouteState Highway 18
CountyBoone County
StateKentucky
Coordinates39.00139, -84.64722
Functional classUrban Minor Arterial

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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 2023
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 alignment6: Equal to present minimum criteria
Operating rating63.4 US tons
Inventory rating38 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length276 ft (84.1 m)
Longest span78 ft (23.8 m)
Deck width90 ft (27.3 m)
Roadway width82 ft (25 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic53,570 (2023)
Projected traffic53,570 by 2043
Trucks14%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
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 statusPossibly eligible for the National Register; requires further investigation
Work proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was KY-18 over I-75 built?

It was built in 1960, making it 65 years old in 2025.

What condition is KY-18 over I-75 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 June 2023.

How much traffic does KY-18 over I-75 carry?

About 53,570 vehicles per day (2023 count), of which roughly 14% are trucks.

How long is KY-18 over I-75?

The structure is 276 ft (84.1 m) long with a longest span of 78 ft (23.8 m) and a deck 90 ft wide.

Who owns KY-18 over I-75?

It is owned by the State Highway Agency.