Outside of Rush, NY 15A takes on a more northeasterly alignment as it passes Rush's town reservoir and enters the town of Henrietta. The surroundings initially remain as rural as they were in Rush; however, the amount of development along the highway gradually increases as the route approaches and passes over the New York State Thruway (I-90). One mile (1.6 km) later, NY 15A intersects NY 253 in a densely populated area west of Rush–Henrietta Senior High School. The homes continue for another to the Monroe County Fairgrounds (home to The Dome Center), at which point NY 15A begins to become lined with commercial establishments. The trend temporarily ceases around an interchange with I-390—where NY 15A curves northwestward—but resumes ahead of a junction with NY 252, itself a major commercial strip.