Route 93 was commissioned in 1932, and followed today's Route 169, from Norwich into Massachusetts. It was changed to 169 in 1959, to avoid a numbering conflict in Massachusetts with Interstate 93. Had old Route 93 not crossed a state line, it might have kept its number.

Another route renumbered (partially) for the same reason: part of Route 190 became Route 168 in 1977 when Interstate 190 opened in Massachusetts.