At the intersection with Slade Avenue, NY 240 and Orchard Park Road turn north at Slade Road, which connects to the New York State Thruway's exit 55 at CR 137. NY 240 proceeds north through West Seneca, passing several residences and businesses before crossing over Cazenovia Creek into a large residential district. In this large residential district, NY 240 intersects with NY 16, which connects to NY 400 (Aurora Expressway) a short distance to the east. NY 240 proceeds north as Harlem Road, paralleling the New York State Thruway just past exit 54, which serves as the northern terminus of NY 400. Crossing under NY 400, NY 240 crosses over more railroad tracks and intersects with CR 109 (Indian Church Road).