The Acela 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 miles per hour (240 km/h) (qualifying as high-speed rail), but only over 49.9 miles (80.3 km) of the 457-mile (735 km) route.
Acela carried more than 3.4 million passengers in the fiscal year 2016; second only to the slower and less expensive Northeast Regional, which had over 8 million passengers. Its 2016 revenue of $585 million was 25% of Amtrak’s total.
Acela operates along routes that are used by freight and slower regional passenger traffic, and reaches the maximum allowed speed of the tracks only along some sections, with the fastest peak speed along segments between Mansfield, Massachusetts, and Richmond, Rhode Island, and New Brunswick and South Brunswick (Trenton in 2024), 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.
According to en.wikipedia.org; Source of photos: internet