which places are connected by new york state route 146?
Gallupville, Mechanicville and Schenectady.
New York State Route 146
It extends for from Gallupville at NY 443 to near Mechanicville at U.S. Route 4 (US 4) and NY 32. NY 146 is a major thoroughfare in the city of Schenectady, just outside Albany. Most of the route follows an east–west alignment; however, the middle third of the route between Guilderland and Clifton Park runs in a more north–south manner in order to serve Schenectady. 
wiki:23139961
New York State Route 146 [SEP] Introduction
NY 146 was assigned as part of the 1930 renumbering of state highways in New York. At the time, NY 146 began at modern NY 443 in Berne and followed what is now NY 156 northeast to Altamont while modern NY 146 west of Altamont was part of NY 156. The alignments of the two routes were flipped in the late 1930s. Other minor realignments have occurred since, most notably near Mechanicville.