The remaining portions of modern NY 28 were unnumbered.

The highway was completed by 1929 and extended from modern NY 30 north to a dead end at Warren Point.

The entirety of modern NY 369 was assigned in the 1930 renumbering.

Lastly, the portion south of modern NY 31 was added in the late 1920s.

Other portions of modern NY 149 were constructed over the course of the next decade.

The remainder of modern NY 149 was unnumbered prior to 1930.

It continued to Cortland by way of modern NY 215.

South of Hornell, the route followed modern NY 36.

From 1927 to the late 1930s, modern NY 15 was part of NY 2.

In the mid-1920s, three sections of modern NY 63 received posted route numbers for the first time.