When the state's highway system was first signed in 1919, there was a different M-14 that ran the length of the Lower Peninsula of Michigan. This was later replaced by a pair of different US Highways in the 1920s and 1930s. Another M-14 was designated that lasted until the 1940s. The current highway dates back to 1956 when it was designated along a series of roads that previously carried US 12. During the 1960s and 1970s, M-14 was moved to the freeway alignment it currently uses; sections of the former route are still maintained by the Michigan Department of Transportation (MDOT) as unsigned highways.