I-365 and I-66 in Kentucky: Two Corridors, One Shared Roadway

“I-365 and I-66 are not rivals for the same road, they are two federally authorized corridors sharing the same 88 miles of Kentucky pavement, and neither cancels the other.”

— Robert Spurlock, President/Executive Director of TransAmerica Corridor, Inc.

I-365 and I-66 in Kentucky: Two Corridors, One Shared Roadway

By Robert Spurlock

While only about five years old now, it’s become a common point of confusion. Kentucky’s south-central corridor carries a lot of history, and lately it carries two federal highway designations as well. That has led to an understandable question from stakeholders and supporters: now that the Louie B. Nunn Cumberland Expressway has been designated Interstate 365, does that mean the Future I-66 Corridor is no longer part of the plan for this stretch of Kentucky?

The answer is no.

I-365 and I-66 are two separate, congressionally recognized corridors that happen to share the same physical roadway across south-central Kentucky. One does not cancel or substitute for the other, and both remain fully intact under federal law.

TWO DIFFERENT CORRIDORS, TWO DIFFERENT PURPOSES

Congress designates “High Priority Corridors” individually, under Section 1105(c) of the Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA), and each one is numbered and defined on its own terms. Corridor 3 and Corridor 97 were established for different reasons and serve different roles in the National Highway System.

High Priority Corridor 3 — the East-West TransAmerica Corridor (Future I-66): A congressionally authorized, eleven-state corridor running from Hampton Roads, Virginia, to the Pacific coast at San Diego and San Luis Obispo, California. In Kentucky, the statutory route description runs through Pikeville, Jenkins, Hazard, London, and Somerset, then generally follows the Louie B. Nunn Parkway corridor from Somerset to Columbia, to Glasgow, to I-65, before continuing to Bowling Green, Hopkinsville, Benton, and Paducah.

High Priority Corridor 97 — the Louie B. Nunn Cumberland Expressway (Future I-365): A single-state Kentucky corridor, added to the ISTEA list at the request of the Kentucky congressional delegation, covering the expressway from its interchange with I-65 in Barren County east to US 27 in Somerset. Its federal legislation designates it specifically as a spur of Interstate 65. This is the same numbering convention used nationwide for three-digit auxiliary routes that branch from a two-digit parent interstate.

In short: Corridor 3 (I-66) is a national, multi-state corridor connecting two coasts. Corridor 97 (I-365) is a state-level auxiliary spur tied to I-65. They were authorized under different provisions, for different purposes, and neither statute purports to repeal or replace the other.

SAME PAVEMENT, DIFFERENT DESIGNATIONS

The overlap that has caused confusion is straightforward once the two statutory descriptions are placed side by side: the Corridor 3 (I-66) route description already routes traffic over the Louie B. Nunn Parkway between Somerset and I-65 near Glasgow. The identical stretch of roadway that Corridor 97 covers under its own designation. That is not a conflict. It is a single physical roadway carrying two federally recognized corridor identities at once, each authorized by its own act of Congress.

This is routine practice on the Interstate System. Concurrent designations (two interstate numbers sharing one physical route) exist across the country, including within the Future I-66 Corridor itself, where Future I-66 and Future I-73 share a common alignment through Williamson, West Virginia, under the same Corridor 3 statutory language. A roadway carrying more than one interstate designation is a matter of shared signage and overlapping federal recognition, not a substitution of one route for another.

The Kentucky Transportation Cabinet’s own planning documents confirm this dual purpose directly. KYTC’s Fiscal Year 2020-2026 Highway Plan lists a project to modernize the Louie B. Nunn Parkway explicitly “for possible utilization as a portion of I-66” – the same roadway the state is separately studying for conversion to I-365. The state is not treating these as competing futures for the same pavement; it is treating them as complementary.

It is also worth being precise about where I-365 currently stands: the 2021 federal infrastructure law added the corridor to the High Priority Corridor list and specified that it would be designated as a spur of I-65, but the roadway does not yet meet Interstate design standards. A March 2022 KYTC study identified roughly $26.4 million in improvements needed just to bring the expressway to a minimum “initial conversion” standard, and $41.5 million for full compliance with Interstate design criteria. This includes shoulder widening, guardrail upgrades, bridge railing replacement, and a full rebuild of the Exit 27 interchange among them. I-365 is a confirmed federal designation, but the physical conversion to a signed Interstate is still a funded, multi-year undertaking, not something already completed.

It’s also worth naming who has been driving the I-365 effort locally, since that helps explain why it is a state-level spur push rather than an attempt to supplant the national, multi-state, I-66 Corridor. The Somerset-Pulaski Economic Development Authority (SPEDA), together with three Touchstone Energy electric cooperatives (South Kentucky RECC, Taylor County RECC, and Farmers RECC), initiated the push in 2020 to study and pursue an I-65 spur designation for the parkway, framed explicitly as an economic development tool for Somerset-Pulaski County and the communities along the route. Kentucky’s congressional delegation (Senator McConnell and Representatives Guthrie, Rogers, and Comer) carried that request into the legislation that ultimately became the 2021 designation. None of that advocacy purported to replace or compete with the separate, much larger I-66 TransAmerica Corridor effort; it was aimed squarely at the spur.

That same local leadership now has a direct hand in the I-66 Corridor effort as well. SPEDA President & CEO Chris Girdler joined the TransAmerica Corridor, Inc. Board of Directors in late 2025, giving Somerset-Pulaski County a seat at the table pushing for the full, East-West TransAmerica Corridor. This is same person helping steer both the local I-365 spur and the national I-66 Corridor push, from two distinct seats representing two distinct, complementary efforts.

You can review our current TAC Board of Directors here: https://transamericacorridor.com/leadership/

WHY THE DISTINCTION MATTERS

For TransAmerica Corridor, Inc. (TAC), the distinction is more than technical. Our mission is to advance completion of the full, eleven-state Future I-66 Corridor authorized under Corridor 3, not a single state’s spur route. Confusing the two designations risks understating the scope of what Congress has already authorized, and risks giving the impression that a state-level spur designation somehow satisfies or supersedes the much larger multi-state authorization that Corridor 3 represents.

It does not.

Canceling a congressionally designated High Priority Corridor requires an Act of Congress, and no such action has been taken with respect to Corridor 3. The I-365 designation adds a complementary, locally significant federal recognition to a segment of roadway that was already part of the I-66 corridor’s authorized route. It does not remove that segment from Corridor 3, and it does not affect the corridor’s larger, unbuilt (and non-statutory) segments extending west through Kansas and the corridor’s proposed western extension toward Colorado, New Mexico, Arizona, Utah, Nevada, and California.

THE BOTTOM LINE

I-365 is good news for south-central Kentucky. It brings a federal spur designation to the Louie B. Nunn Cumberland Expressway that can help attract funding and investment along that stretch of roadway. It is also good news for the I-66 Corridor, because the same infrastructure improvements that benefit I-365 travelers also benefit the segment of Future I-66 Corridor that runs concurrently with it.

Two designations, one roadway, one shared purpose: connecting Kentucky communities to a national transportation network. TAC will continue to advocate for full completion of the twelve-state I-66/I-50 Corridor, including this Kentucky segment, regardless of how many additional designations that segment carries.

TransAmerica Corridor, Inc. (TAC) is a 501(c)(4) nonprofit advancing completion and extension of the congressionally authorized East-West TransAmerica Corridor (High Priority Corridor 3) from Hampton Roads, Virginia, to San Diego (and one day, San Luis Obispo, California).

Robert Spurlock is the President/Executive Director  of TransAmerica Corridor, Inc.  To learn more about the organization visit www.transamericacorridor.com or contact him at Robert.Spurlock@transamericacorridor.com.

Sources

1. SPEDA on leading the I-65 spur (I-365) initiative with Touchstone Energy cooperatives (2020) — https://somersetkyleads.com/speda-touchstone-energy-lead-interstate-65-spur-project/
2. Congressman Guthrie, Senator McConnell, Reps. Rogers and Comer reintroduce Cumberland Expressway spur legislation (2021) — https://guthrie.house.gov/news/documentsingle.aspx?DocumentID=387374
3. Congressman Comer press release on original Cumberland Parkway spur legislation (2020) — https://comer.house.gov/2020/10/mcconnell-guthrie-rogers-comer-introduce-cumberland-parkway-legislation
4. FHWA official list of High Priority Corridors and Future Interstates (Corridor 3 and Corridor 97) — https://www.fhwa.dot.gov/Planning/national_highway_system/high_priority_corridors/hpcfitext.cfm
5. KYTC Cumberland Expressway Upgrade Study, Final Report (March 2022) — https://transportation.ky.gov/Planning/Planning%20Studies%20and%20Reports/Cumberland%20Expressway%20Upgrade%20-Final%20Report.pdf
6. H.R. 2470, 117th Congress — Louie B. Nunn Cumberland Expressway designation bill text — https://www.govinfo.gov/content/pkg/BILLS-117hr2470ih/pdf/BILLS-117hr2470ih.pdf