terminated at Washington, D.C. between 1995–2002. Replacement At the end of 2012, 473 Amfleet I and 145 Amfleet II cars were still in service. The Amfleet I cars had traveled an average of , the Amfleet II cars . The Amfleet I cars continue to be used on corridor services in the Northeastern United States such as the Downeaster, Empire Service, and Northeast Regional, although they can also be found in the Midwest and California. Amfleet IIs continue to be used on single-level long-distance trains. Amtrak announced an overhaul of the Amfleet I interiors in September 2017. The following year, Amtrak began to investigate options to replace the Amfleet I cars altogether. In January 2019, Amtrak issued a request for proposals to replace the 470 Amfleet I cars and ex-Metroliner cab cars then in use. Proposals were due on May 1, 2019. In May 2020, excursion operator Railexco purchased three Amfleet cars from Amtrak – the first Amfleet cars to be sold for private reuse. By February 2021, Amtrak planned for the replacements to be trainsets rather than individual cars, with options for diesel, electric, or dual-mode propulsion. Siemens was announced as the preferred bidder in April 2021, with contract execution for 83 trainsets expected midyear. The equipment is expected to be delivered between 2025 and 2035. In July 2021, it was announced that $7.3 billion would be put towards the new equipment. In 2022, Amtrak announced that it plans to begin retiring Amfleet I cars by 2027, with all cars to be retired by the end of 2030. In December 2022, Amtrak reached an agreement with Siemens for 83 "Airo" trainsets for delivery starting in 2026, at which time they would begin by replacing the Amtrak Cascades fleet. After replacing the Cascades fleet, the Airo would begin the process of replacing the Amfleet I fleet in 2027. Design As designed, the Amfleet I cars could operate at speeds up to . Both the Amfleet I and Amfleet II are now rated for . Electric heating and air conditioning, operated by head-end power (HEP) from the locomotive, are used to maintain passenger comfort. Budd moved the air vents from the bottom, where they had been on the Metroliner, to the top of the car. The top-mounted vents were less susceptible to clogging during snowfall. An Amfleet car is tall, wide, and long. The car body itself is built up from