 In the 1930 renumbering of state highways in New York, the NY 3A through NY 3C and NY 3E designations were assigned to four spur routes of NY 3 in western and central New York.By the following year, a connector linking NY 3 in New Haven to NY 3C in the town of Mexico via the hamlets of New Haven, Demster, and Texas was designated as NY 3D.The suffixes of all of NY 3's suffixed routes were increased by one letter (A to B, and so on) following the establishment of a new NY 3A in Niagara County.