Thursday, March 26, 2015

Redesign of interchange to preserve interstate access for Calvert City

A redesign of an interchange will preserve interstate access for 
Calvert City.
Engineers designing the corridor for Interstate 69 can rebuild a key interchange for Interstate 24 in Marshall County in a way that preserves direct interstate access to U.S. 62 at Calvert City.

“The project team has come up with a design that accomplishes two important objectives,” Gov. Steve Beshear said last Wednesday. “It will result in an interchange that meets federal interstate standards. At the same time, it will maintain a critical connection for Calvert City.”

The key to the project will be construction of a separate ramp – called a “flyover” ramp – to afford traffic an exit from I-69 North onto the Julian M. Carroll Purchase Parkway, which directly connects with U.S. 62 and Ky. 1523 – Oak Park Boulevard – in Calvert City.

Reconstruction of the interchange is part of a larger project to upgrade the Purchase Parkway to become part of I-69. When the corridor is complete, I-69 will run north to south from the Ohio River at Henderson to the Tennessee line at Fulton. In addition to the Purchase Parkway, the corridor includes sections of I-24, the Wendell H. Ford Western Kentucky Parkway and the Edward T. Breathitt Pennyrile Parkway.

A contract for the project is expected to be awarded this fall.

The I-24/Purchase Parkway interchange lies at the western end of an 18-mile segment of interstate on which I-69 and I-24 run concurrently. This interchange is unique in that it involves a major fork where two interstates combine. Under the project design, the interstates will split immediately east of the interchange. Traffic continuing west on I-24 will bear to the right. Traffic going south on I-69 will peel off to the left.

Federal Highway Administration (FHWA) rules for interstate highways require “route continuity” – meaning traffic staying on a particular interstate route within the confines of an interchange must be able to do so seamlessly, with no loss of speed.

However, there is no such requirement for traffic switching from one interstate route to another – in this case, from I-69 northbound to I-24 westbound. FHWA has approved retention of a cloverleaf ramp for this traffic movement.

Initial alternates for the interchange considered eliminating some or all of the cloverleaf ramps, and with them the existing connection to U.S. 62 at Calvert City. The new design preserves three of the existing cloverleaf ramps. It eliminates a fourth ramp that currently serves as the Fulton exit for I-24 westbound traffic. The design also eliminates the ramp that currently serves as the Nashville exit for northbound parkway traffic merging into I-24 East/I-69 North. In place of that ramp will be the new mainline I-69 movements and the flyover ramp for Calvert City.