 By 1926, all of legislative Route 30 west of Rochester was designated as part of NY 31.At the time, the entirety of Ridge Road outside of the city of Rochester was state-maintained; however, the piece west of Porter and the section in Irondequoit between the Genesee River and Irondequoit Bay were both unnumbered.The former became part of a realigned NY 31 in the late 1920s, while the latter became part of an extended NY 18  following the completion of the Veterans Memorial Bridge over the Genesee River.