Photo by Kevin H.

Later this week, Amtrak will begin test runs of truly high-speed trains along its Northeast Corridor between Washington and Boston, the train service announced yesterday.

Trains across four stretches will run at 165 miles per hour as Amtrak attempts to match the U.S. record for rail speed. Amtrak is in the middle of a decades-long process of expanding and enhancing the Northeast Corridor—its most heavily traveled route—that will cost an estimated $151 billion by the time work is completed in 2040.

The closest test area to D.C. is a 21.3-mile stretch between Perryville, Md. and Wilmington, Del., where beginning Thursday night, an empty Acela train will shuttle back and forth reaching 165 miles per hour. The speed limit along that section is 135 miles per hour, though pace felt by riders is often much slower.

Although Acela trains are capable of going 165 miles per hour, the average speed between Washington and Boston is closer to 80 mph between D.C.’s Union Station and New York Penn Station; it reaches 150 miles per hour on a few sections of track in Rhode Island.

But Acela and the regular Northeast Regional combined serve nearly 10.5 million passengers a year, making Amtrak the most popular intercity travel option in the Northeast. In fact, the Baltimore Sun reports, Southwest Airlines recently stopped offering flights between its hub at Baltimore-Washington International Airport and LaGuardia Airport and Newark Liberty International Airport.

In July, Amtrak unveiled plans to radically overhaul Union Station as it seeks to increase its schedule of high-speed trains. The centerpiece of the redesign is a massive new concourse dedicated to a high-speed train network, though it will be well into the 2030s before that network is up and running.