In the United States, future Interstate Highways include proposals to establish new mainline (one- and two-digit) routes to the Interstate Highway System. Included in this article are auxiliary Interstate Highways, designated by three-digit numbers, in varying stages of planning and construction, and the planned expansion of existing primary Interstate Highways.
State Route 99 has been designated as a future Interstate Highway corridor between Wheeler Ridge and Sacramento. The route would be designated as I-7 or I-9, remaining in line with the national numbering system. Differing proposals show the route ending in Stockton or Sacramento. Designation is contingent upon completion of the "Route 99 Corridor Enhancement Master Plan". Although scattered improvement projects have been completed, there is currently no timeline or funding for the completion of the plan.
The current Interstate 695 will be eliminated and be replaced with an extension of Interstate 395. The original Interstate 395 through the 3rd Street Tunnel will be renumbered as Interstate 195.
Interstate 222 is a future auxiliary Interstate Highway that will be a connector between I-22 and the proposed I-422 near Birmingham, Alabama. There will be no exits other than its termini. The highway has been proposed because an interchange directly between I-22 and I-422 cannot be built due to environmental issues.
Interstate 274 is the future designation for the western half of the beltway, currently designated as NC 452. When completed, it will connect US 158, near Clemmons, North Carolina, to Future I-74/Future I-285/US 52, in Bethania. I-274 first appeared on North Carolina Department of Transportation (NCDOT) planning maps in the early 2000s but was later disused for over a decade since. In May 2019, the American Association of State Highway and Transportation Officials (AASHTO) approved a request to establish Future I-274. Justification given by NCDOT was that the 16.83-mile (27.09km) section would satisfy a great need to alleviate congestion in Winston-Salem, and connect the western portion of the urbanized area.
Interstate 365 is a proposed redesignation of the Cumberland Expressway once it is upgraded to Interstate standards. In August 2021, Congress released a new infrastructure bill that proposed to designate the whole length of the Cumberland Expressway as a Future Interstate, with the designation of I-365. The designation would need approval from AASHTO, the FHWA, and upgrades of several interchanges and other improvements before the designation could be implemented.
Interstate 369 is planned to follow the entire Audubon Parkway. The western terminus to Interstate 69 will be called the Interstate 69 Spur.[failed verification]
Interstate 422 is a proposed beltway in Birmingham. Interstate 422 will not directly connect to I-22 so therefore a new connector known as Interstate 222 is proposed. It is also called Corridor X-1. The first segment opened in September 2026 as State Route959.
In April 2019, the Western Kentucky Parkway was proposed as Interstate 369. In December 2019, it was changed to Interstate 569, as the Audubon Parkway was proposed to be Interstate 369.
Interstate 685 is a proposed Interstate planned to run along current US 421. It will be upgraded to Interstate highway standards from Interstate 40 in Greensboro to Interstate 95 in Dunn.
123"Chapter 3". Caltrans Route 99 Enhancement Plan(PDF). California Department of Transportation. Archived from the original(PDF) on February 4, 2010. Interstate designation, under the current proposal, would apply to the 260-mile (420km) segment between the junction of SR99 with I-5 south of Bakersfield to I-5 in Stockton using State Route 4 as the connector to I-5. Since there is an I-99 route currently in existence in Pennsylvania, it is anticipated that should designation be granted, the SR99 designation would become I-7 or I-9 to satisfy Interstate numbering convention.
↑Special Committee on U.S. Route Numbering (May 19, 2012). "Report to SCOH"(PDF) (Report). Washington, DC: American Association of State Highway and Transportation Officials. Archived from the original(PDF) on June 3, 2019. Retrieved January 24, 2025.
.svg)
.svg)
.svg){kind=small}
.svg){kind=small}
.svg){kind=small}
.svg){kind=small}
.svg){kind=small}
.svg){kind=small}
.svg){kind=small}
.svg){kind=small}
.svg){kind=small}
.svg){kind=small}
.svg){kind=small}
.svg){kind=small}
.svg){kind=small}
