Amtrak operates on 21,000 miles (34,000 kilometers) of tracks throughout the United States. The Northeast Corridor (NEC) is the most highly-traveled portion of the network with service to many cities including Boston, New York, Philadelphia, Baltimore, and Washington, D.C. Outside of the Northeast, the regional service in California is the only other route with significant, heavy volume. The Amtrak stations with the most boardings are: New York's Penn Station, Washington D.C.'s Union Station, Philadelphia's 30th Street Station, Chicago's Union Station, Los Angeles' Union Station, and Boston's South Station. Amtrak accepts the Amtrak USA Rail Pass.



