Acela
The Acela is Amtrak's flagship passenger train service along the Northeast Corridor 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, qualifying as high-speed rail, but only for approximately of the 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 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, 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 speed is limited by traffic and infrastructure on the route's northern half. On the 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. Along this section, Acela has captured a 54% share of the combined train and air market. The entire route from Boston to Washington takes between 6 hours, 38 minutes and 6 hours, 50 minutes, at an average speed of around.
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.
History
Background
Following the success of Japan's newly inaugurated Shinkansen network in the 1960s, the High Speed Ground Transportation Act of 1965 authorized the U.S. government to explore the creation of high-speed rail, which resulted in the introduction of the higher-speed Metroliner trains between Washington, D.C., and New York City in 1969, the predecessor to Acela. During the 1980s, the U.S. Federal Railroad Administration explored the possibilities of high-speed rail in the United States. On December 18, 1991, five potential high speed rail corridors were authorized, including the Northeast Corridor.In the early 1990s, Amtrak tested several different high-speed trains from Europe on the Northeast Corridor. An X 2000 train was leased from Sweden for test runs from October 1992 to January 1993, followed by revenue service between Washington, D.C., and New York City from February to May and August to September 1993. Siemens showed the ICE 1 train from Germany, organizing the ICE Train North America Tour which started to operate on the Northeast Corridor on July 3, 1993.
Building and development
With the testing of the trains from Europe complete, Amtrak was able to define a set of specifications for high-speed equipment and in October 1994, Amtrak requested bids from train manufacturers for a trainset that could reach. A consortium of Bombardier and GEC Alsthom was selected in March 1996.In 1999, Amtrak unveiled its plan for the Acela Express, a high-speed train on the Northeast Corridor between Washington, D.C., and Boston. Several changes were made to the corridor to make it suitable for higher-speed electric trains. The Northend Electrification Project extended existing electrification from New Haven, Connecticut, to Boston to complete the overhead power supply along the route, and several grade crossings were improved or removed. Prior to 2000, all trains bound for Boston had to switch to diesel power at New Haven.
A pilot trainset was completed by early 2000 and sent to Transportation Technology Center for testing in June 2000. An inaugural VIP run of the Acela occurred on November 16, 2000, followed by the first revenue run on December 11, 2000, a few months after the intended date.
Cost
Amtrak's original contract with the Bombardier-Alstom consortium was for the delivery of 20 trainsets for $800 million. By 2004, Amtrak had settled contract disputes with the consortium, paying a total of $1.2 billion for the 20 trainsets plus 15 extra high-speed locomotives and the construction of maintenance facilities in Boston, New York, and Washington.Impact of the ''Acela''
By 2005, Amtrak's share of the common-carrier market between New York and Boston had reached 40%, from 18% pre-Acela. With the increasing popularity of the faster, modern Acela Express, Metroliner service was phased out in late 2006. To meet the demand, more Acela services were added in September 2005. By August 2008 crowding had become noticeable.By 2011, the Acela fleet had reached half of its designed service life. Amtrak proposed several replacement options, including one as part of its A Vision for High-Speed Rail in the Northeast Corridor. In 2011, Amtrak announced that forty new Acela coaches would be ordered in 2012 to increase capacity on existing trainsets. The existing trains would have received two more coaches, lengthening the trainsets from a 1-6-1 configuration to 1-8-1. The longer trainsets would have required the modifications of the Acela maintenance facilities in Boston, New York and Washington. The first of the stretched trainsets was to have entered service in fiscal year 2014. This plan was cancelled in 2012 in favor of replacing, rather than refurbishing, the Acela fleet.
In January 2014, Amtrak issued a request for proposals on 28 or more new model Acela trainsets, in a combined order with the California High-Speed Rail Authority. After discussions with manufacturers, Amtrak and the California High Speed Rail Authority concluded their needs were too disparate for common rolling stock and decided not to pursue the joint option.
Legacy and influence
Since its introduction, the Acela has become a symbol of modern passenger rail in the United States and has influenced subsequent high-speed rail planning efforts across the country. The Train's operational success demonstrated consistent public demand for faster, business-oriented intercity travel, reinforcing federal and state interest in high-speed rail corridors such as California High-Speed Rail and Brightline West. Amtrak's experience with Acela's maintenance and ridership patterns has also informed the design of future services and infrastructure standards along the Northeast Corridor and beyond.Branding
Before the introduction of the Acela, there were several classes of trains on the Northeast Corridor: the express Metroliners, the Philadelphia-New York Clockers, Empire Service trains between New York City and Niagara Falls via the Empire Corridor, Keystone Service trains between New York City and to Harrisburg via the Keystone Corridor, and the umbrella term NortheastDirect, applied to other trains on the corridor.The Acela name was announced in 1999 as a part of the original announcement of the service itself. The branding team based the name "Acela" on the ideas of acceleration and excellence. At the same time, Amtrak launched what it called the Capstone Program, a short-lived plan to rebrand the NortheastDirect, Keystone Service and Empire Service trains as Acela Regional and the Clocker trains as Acela Commuter.
The Acela Regional name was first applied to NortheastDirect trains 130–133 in 2000. Those trains were the first electrified trains to run on the full Northeast Corridor between Washington, D.C., and Boston. As more trains were electrified, they too were rebranded.
Following widespread rider confusion among the three services, the branding was removed from the lower-speed Acela Regional and Acela Commuter trains in 2003.
In 2019, Amtrak shortened the name of the service from Acela Express to simply Acela.
Engineering
First-generation trainsets
The first-generation Acela trainset is a unique set of vehicles designed specifically to satisfy governmental rolling stock requirements established primarily by the Federal Railroad Administration. This includes the ability to withstand a collision with a freight train at speed without collapsing. Most manufacturers that bid on the Acela were unable to meet the structural requirements, due to increased costs and complications for the manufacture of the trains, and the need for manufacturers to make significant engineering changes to their standard designs. In the end, only three qualified bidders remained: ABB, Siemens, and a consortium of Bombardier and Alstom.The design, using identical power cars at each end which operate on voltages of 12 kV, 12.5 kV, and 25 kV AC, and either 25 or 60 Hz frequency, derives several components from the TGV, such as the third-generation TGV's traction system, the trucks/bogies structure, the brake discs, and crash energy management techniques to control structural deformation in the event of an accident.
The tilting carriages are based upon Bombardier's earlier LRC trains used on Via Rail rather than the TGV's non-tilting articulated trailers. Acela power cars and passenger cars are much heavier than those of the TGV in order to meet the FRA's crash standards. French and Canadian crews testing the Acela referred to it as "the pig" due to its weight. The extra weight leads to the Acela power-to-weight ratio being about 22.4 hp per tonne, compared to 30.8 hp for a SNCF TGV Reseau trainset. The Tier II crash standards, adopted in 1999, have also resulted in the passenger cars being designed without steps and trapdoors, which means that the trainsets can only serve lines with high-level platforms such as the Northeast Corridor. Acela trains are semi-permanently coupled and are referred to as trainsets. Bombardier later used the Acela carriage design and a diesel/gas turbine variant of the power car for its experimental JetTrain.