US Bridges

I-75 over Ky 18 Ramp

Fair

Boone County, Kentucky · I75 Rmp to US 42 · Structure no. 008B00072N

Built
1990
35 years old
Condition
Fair
inspected June 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
118 ft
1 main span
Daily traffic
140,378
2023 count
Owner
State
State Highway Agency

About this bridge

I-75 over Ky 18 Ramp is a prestressed concrete stringer/multi-beam or girder carrying I-75 over Ky 18 Ramp in Boone County, Kentucky. It was built in 1990, so it is 35 years old, younger 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 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 140,378 vehicles a day, roughly 15% of them trucks, projected to reach 154,415 by 2043. The structure is 118 ft (36 m) long and 37 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesI-75
CrossesKy 18 Ramp
LocationI75 Rmp to US 42
RouteInterstate 75
CountyBoone County
StateKentucky
Coordinates38.98611, -84.64278
Functional classUrban 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.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Last inspectionJune 2023
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating109.2 US tons
Inventory rating65.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 25 or greater
Structure length118 ft (36 m)
Longest span112 ft (34.1 m)
Deck width37 ft (11.4 m)
Roadway width34 ft (10.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic140,378 (2023)
Projected traffic154,415 by 2043
Trucks15%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was I-75 over Ky 18 Ramp built?

It was built in 1990, making it 35 years old in 2025.

What condition is I-75 over Ky 18 Ramp 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 I-75 over Ky 18 Ramp carry?

About 140,378 vehicles per day (2023 count), of which roughly 15% are trucks.

How long is I-75 over Ky 18 Ramp?

The structure is 118 ft (36 m) long with a longest span of 112 ft (34.1 m) and a deck 37 ft wide.

Who owns I-75 over Ky 18 Ramp?

It is owned by the State Highway Agency.