This set of Interstates includes those that were either signed at one point and legislatively decommissioned, renumbered as another Interstate, or planned and subsequently canceled. As planning documents arise either through library research, the internet, or other sources, expansion of the list below will occur with this information and photos as they are taken.
The following code indicates whether the Interstate was Dismantled (D); Partially Completed (P); Renumbered as another Interstate or freeway designation, U.S., or State Route (R); Unconstructed (U); or Numbering Proposed but Not Approved by AASHTO (N).
* = Route built to expressway/parkway/boulevard standards rather than Interstate standards (controlled access).
Official Route Numbering for the National System of Interstate and Defense Highways adopted by the American Association of State Highway Officials in August 1957.
Some notable changes from the original system envisioned by transportation officials include:
Interstate 31 in North Dakota was renumbered as part of an extended Interstate 29
Interstate 67 between Elkhart and Lansing was never built
Interstate 77 from Detroit to Port Huron became the easternmost extent of Interstate 94
Interstate 78 between Norwalk, Ohio and Youngstown was supplanted by the corridors of Interstate 80 and 80S (later I-76)
Interstate 79 between Canton and Cleveland, Ohio was renumberd as Interstate 77
Interstate 80 from Youngstown southeast to Harrisburg was later changed to I-80N and ultimately I-76. The I-80N/S split east from Harrisburg now carries I-78 and I-76 respectively.
Interstate 82 from Portland to Idaho was redesignated as Interstate 80N. I-82N in Idaho was later I-15W and today is I-86
Interstate 82 between Scranton and New York became I-81E (now I-380) and part of new I-80.
Interstate 84 across northern Pennsylvania was dropped in favor of a southern alignment for new Interstate 80
Interstate 90N between Buffalo and Niagara Falls became Interstate 190
Interstate 92 in Michigan was renumbered as the new alignment of I-94, with planned I-94 being replaced by I-96.
Interstate 94N in Michigan became Interstate 196 and later the westernmost extent of I-96
Interstate 95E from Providence to New Beford changed to Interstate 195
Birmingham, Alabama - 1960.
Interstate 59B was the proposed number for the Birmingham belt line (Interstate 459) in the early days of the Interstate System.
Topeka, Kansas - 1960.
This Topeka, Kansas inset from 1960 shows Interstate 70 Bypass for what is now Interstate 470 bypassing the capital city to the south. Note also the error I-35 shield posted for the Kansas Turnpike (now I-335). Interstate 35 was never envisioned for this stretch of the turnpike.