In the 1920s, State Highway 168 followed today's Route 87.

The original Route 168, commissioned in 1932, connected US 5 and Route 17 on what is now Route 22; it became part of 22 in 1951, to help guide motorists from the Wilbur Cross Parkway to US 1.

The modern Route 168 was originally part of Route 190, which extended west to US 202/MA 10. The numbering was switched in 1977, to avoid conflicts between state route 190 and Interstate 190 in Massachusetts.

• "Route marks planned on links to parkways." Bridgeport Sunday Post, April 22, 1951.

• Route 168 Ends (Photos; Doug Kerr at state-ends.com)
• MA 168 (Dan Moraseski)