New York State Route 78

New York State Route 78 (NY 78) is a 73.49-mile (118.27 km) state highway in western New York in the United States. While it is signed north–south, the southern portion runs in an east–west direction across Wyoming and Erie counties, from its beginning at a junction with NY 19 north of the village of Gainesville to the village of East Aurora. The part of the route north of East Aurora follows a generally north–south alignment to an intersection with NY 18 in the Niagara County town of Newfane (at the hamlet of Olcott), just south of the Lake Ontario shoreline. The route is most closely identified in the region with Transit Road, a major north–south trunk road through the center of Erie and Niagara counties; however, NY 78 does not follow Transit Road for its entire length, nor does Transit Road comprise more than half its length. The highway joins Transit Road north of East Aurora and stays with the road to its end in the city of Lockport.

The section of NY 78 between NY 5 in the town of Amherst and the Lake Ontario shoreline in Newfane was originally designated New York State Route 32 in the mid-1920s. In the 1930 renumbering of state highways in New York, NY 32 was absorbed into NY 78, which ran from Gainesville to Newfane upon assignment. From East Aurora to Depew, NY 78 originally used a slightly more easterly alignment along several local streets and a section of NY 422. Two realignments in the 1930s moved the route onto its modern alignment, and NY 78's original routing between East Aurora and Depew was briefly designated NY 78A during the mid-1930s.