Amtrak Express is a service provided by Amtrak, the national rail system in the United States. The service, known as Acela, offers high-speed rail service along the Northeast Corridor between Washington, D.C., New York City, and Boston. Acela provides travelers with a fast, convenient, and comfortable way to travel between these cities. It is the only high-speed rail service in the United States and is the fastest way to get from one city to another.