New York State Route 400 (NY 400) is a state highway located within Erie County, New York, in the United States. The northwest end is connected to the New York State Thruway (Interstate 90 or I-90) and the southeast end terminates at NY 16 in the town of Aurora. NY 400, a limited-access highway known as the Aurora Expressway, roughly parallels NY 16 between the two locations. It is most commonly used to carry traffic from Buffalo to the village of East Aurora, where Fisher-Price and Moog, Inc are headquartered. It is a busy commuter route to the southern suburbs. NY 400 is signed as a north–south route, although about half of the route runs more east–west.