The Amtrak Cascades line, which Curbed named one of the most scenic train routes in the United States, has brand-new locomotives starting this week. The corridor stretches 467 miles from Vancouver, British Columbia to Eugene, Oregon, with stops in Portland, Seattle, Tacoma, and several other cities.

Most of the train, like the passenger cabins and baggage cars, won’t experience changes, the engines pulling them will. The new Siemens Charger locomotives, with 16-cylinder, 4,400-horsepower engines, are both lighter and quieter, and meet EPA emission standards.

The trains will travel the same speed as before—79 miles per hour—but they’ll reach the top speed faster. While they’re not allowed to go any faster than that, theoretically these trains could travel up to 125 miles per hour.

They also include on-board safety equipment. Amtrak is working on installing a system corridor-wide next year that will allow trains to automatically stop in the event of something dangerous on the track.

Design-wise, the locomotives feature the green and crimson Cascades colors to match the existing cars, and feature logos of both the Washington and Oregon state departments of transportation, which jointly own and manage the service.

The trains will be phased in over the next few weeks. The line operates with an engine on each end—first, trains will run with a new locomotive on one end and an older one on the other, with a new one either pushing or pulling at all times. The old F-59 locomotives, which were built in the mid 1990s, will be phased out over the next year.

The upgrade is part of a larger, $800 million improvement package, which includes 20 federally-funded projects around the state.