Acela

The Acela (/əˈsɛlə/ ə-SEL-ə; originally the Acela Express until September 2019) is Amtrak's flagship passenger train service along the Northeast Corridor (NEC) in the Northeastern United States between Washington, D.C., and Boston via 13 intermediate stops, including Baltimore, New York City and Philadelphia. Acela trains are the fastest in the Americas, reaching 150–160 miles per hour (240–260 km/h), qualifying as high-speed rail, but only for approximately 40 miles (64 km) of the 457-mile (735 km) route.

In fiscal year 2025, Acela carried more than 3.1 million passengers, second only to the slower and less expensive Northeast Regional, which had over 12 million passengers. Ridership was down from the pre-COVID-19 pandemic high of 3,557,455 passengers in 2019. Its 2025 revenue of $570 million was around 20.6% of Amtrak's total.

Acela operates along routes that are used by slower regional passenger traffic, and only reaches the maximum allowed speed of the tracks along some sections, with the fastest peak speed along segments between Mansfield, Massachusetts, and Richmond, Rhode Island, as well as between South Brunswick and Trenton, New Jersey. Acela trains use active tilting technology, which helps control lateral centrifugal force, allowing the train to travel at higher speeds on the sharply curved NEC without disturbing passengers. The high-speed operation occurs mostly along the 226-mile (364 km) route from Pennsylvania Station in New York City to Union Station in Washington, D.C., with a fastest scheduled time of 2 hours and 45 minutes and an average speed of 82 miles per hour (132 km/h), including time spent at intermediate stops. Over this route, Acela and the Northeast Regional service captured an 83% share of air/train commuters between New York and Washington in 2021, up from 37% in 2000.

The Acela's speed is limited by traffic and infrastructure on the route's northern half. On the 231-mile (372 km) section from Boston's South Station to New York's Penn Station, the fastest scheduled time is 3 hours and 30 minutes, or an average speed of 66 miles per hour (106 km/h). Along this section, Acela has captured a 54% share of the combined train and air market. The entire 457-mile (735 km) route from Boston to Washington takes between 6 hours, 38 minutes and 6 hours, 50 minutes, at an average speed of around 70 miles per hour (110 km/h).

The original Acela Express equipment began being replaced by new Avelia Liberty trainsets in 2025. The new trains have greater passenger capacity and an enhanced active tilt system that allows higher speed on the many curved sections of the route. The first five trainsets entered passenger service on August 28, 2025.