Pennsylvania/New York
Connecticut/Massachusetts
There were plans to extend I-84 from Hartford to Providence, RI. The original I-84 from East Hartford to Sturbridge, MA was then called I-86. However, the extension was never completed. I-86 was decommissioned, and I-84 returned to its original route. What was to be I-84 is now a spur route, called I-384.
There used to be signs telling of this project, saying that "I-84 will become I-86." Later, they would read "I-86 is now I-84."