KY 14 (Mary Grubbs Highway) Interchange Modification Phase 1

Project Information

Facility: I-71/75

Location: KY 14 (Mary Grubbs Highway)

Project Type: Roadway Maintenance/Reconstruction

Priority Level: Tier 1

Project Description:

  • Conduct an Interchange Modification Study (IMS) to address capacity and safety issues associated with the southbound I-75 exit ramp approach to the KY 14 intersection.
  • Dedicated dual left turn lanes and a dedicated right turn lane should be considered to improve congestion.
  • Construct the improvements as recommended by the IMS.
  • This recommendation is considered a short-term solution to the overall congestion and safety issues at the interchange.

Cost Estimate:

Planning Design Utilities Right of Way Construction TOTAL
$1,000,000 $130,000 $80,000 $120,000 $900,000 $2,130,000

Benefits:

  • An additional left turn lane will provide more separation between the volume of traffic turning left and the volume of traffic turning right.

Challenges:

  • The proposed improvements to the southbound I-75 ramp to KY 14 serves as a short-term improvement to the existing congestion issue at the interchange.
  • Although this is a minor project, an IMS is required by the Kentucky Transportation Cabinet.  An IMS adds cost to the project and could delay implementation of improvement to address existing transportation needs.

Existing Conditions

Functional Classification: I

  • I-71/75 – Interstate
  • KY 14 – Major Collector

Existing ADT:

  • I-71/75 – 70,770 vehicles per day
  • KY 14 – 3,410 vehicles per day

2040 Forecasted ADT: 

  • I-71/75 – 96,000 vehicles per day
  • KY 14 – 4,300 vehicles per day

Truck Volumes:

  • I-71/75 – 21%
  • KY 14 – 15%

Congestion:

  • The existing ramp from southbound I-75 to KY 14 (Mary Grubbs Highway) is one that widens into two lanes at the ramp terminus. Currently, there is one dedicated right turn lane and one dedicated left turn lane.
  • A large volume of trucks exit I-75 at KY 14 and travel to the existing Flying J rest area, located in the south-west quadrant of the KY 14 (Mary Grubs Highway/Walton Verona Road) intersection with KY 1829 (Beaver Road).
  • There is also a large volume of traffic that exits southbound I-75 at KY 14 to travel to the commercial development east of I-75.
  • The queue of southbound traffic that is turning right at the intersection sometimes extends past the storage that is provided for left turning vehicles, blocking vehicles from turning left at the intersection.

Land Use/Socio-Economic/Environmental:

  • The I-75 interchange at KY 14 serves a mix of commercial, agricultural, and residential land uses.
  • KY 14 connects to US 25 (Dixie Highway) in the City of Walton to the east and to the City of Verona to the west. 

Safety: 

  • The frequency of crashes along KY 14 (Mary Grubs Highway/Walton Verona Road) in this area is over five times the statewide average for similar roadways. Additionally, there was one pedestrian crash on KY 14 (Walton Verona Road) at the southern entrance to the Flying J.
  • The primary crash types along this section of roadway are rear end and sideswipe crashes which indicate congestion and sudden lane changes.