Despite the claim Acela was America's first so-called bullet train it actually only reached its top speed of 150 mph for a stretch of 18 miles between Rhode Island and Massachusetts (the U.S. Department of Transportation officially rates high speed rail at 125 mph).

Amtrak's Acela reaches its maximum operational speed of 150 mph (241 km/h) only on specific segments of the Northeast Corridor (NEC). In 2026, these high-speed bursts occur primarily on the 34-mile stretch between Mansfield, Massachusetts, and Richmond, Rhode Island, and a shorter section in New Jersey between New Brunswick and Trenton. The vast majority of the route between Washington D.C. and Boston is traveled at much lower speeds—averaging 65 to 110 mph—due to aging bridge infrastructure, tight curves in Connecticut, and shared tracks with slower commuter trains. The new Avelia Liberty trainsets, fully integrated into the fleet by 2026, are technically capable of 160+ mph, but they are limited by the existing overhead "catenary" wire systems and track geometry. Despite these limitations, the Acela remains the fastest train in the Western Hemisphere, offering a "city-center to city-center" transit time that is often faster and much more comfortable than flying between NYC and D.C. once you factor in airport security and travel time.