Amtrak has begun replacing rolling stock that in places dates back to the 1970s. Eight new Airo trainsets enter service on the Cascades corridor in autumn 2026. They are the first units of an order for 83 sets from Siemens Mobility, an investment the environmental outlet Grist puts at $8 billion. More than a dozen routes in New England, Pennsylvania and the mid-Atlantic are to follow.
The Cascades line runs about 460 miles from Eugene in Oregon to Vancouver in British Columbia. Each Airo set seats 317 passengers across six coaches. That is 40 percent more than the Talgo Series 8 trains now in service, according to the Seattle outlet The Urbanist. The first set reached Seattle's King Street Station on 16 May 2026 for testing and crew training.
Speed is not the main gain. Amtrak advertises a top speed of 125 mph, barely above the Talgo's 124 mph, the trade publication Railway Supply reports. On the corridor itself trains rarely exceed 79 mph, which Amtrak attributes to track restrictions and freight traffic. Seattle to Portland takes about three and a half hours, roughly as long as the drive.
Cleaner engines, no locomotive swap
The environmental case rests on the hardware. Airo locomotives meet the Environmental Protection Agency's Tier 4 standard, the strictest US rules for locomotive engines. That cuts particulate matter and nitrogen oxides. The sets combine diesel and electric propulsion and can switch between them without changing locomotives.
That matters south of Washington. Passengers travelling between Virginia and the Northeast can wait up to an hour at Union Station while the engine is swapped. Airo trains take over the Northeast Regional route in 2027. Virginia has invested $6 billion in its own rail programme.
"It's a win for the environment, it's a win for the people that are sitting in traffic," Karina Romero, a spokesperson for the Virginia Passenger Rail Authority, told Grist.
Rail already moves 8 percent of the world's passengers while consuming 2 percent of transport energy. Alex Scott, professor of supply chain management at the University of Tennessee-Knoxville, told Grist that a well-filled rail car beats individual cars, electric ones included. Frequency remains the open question. Charlie Hamilton of the group All Aboard Washington wants departures every hour, which he says the new sets would make possible.