California just decided to sharply scale back its plans for a high-speed rail artery meant to transform travel up and down the state. But in the desert outside Las Vegas, the transportation ambitions still seem limitless.  Here, engineers working for Virgin Hyperloop One are testing a radically different type of mass transit: one that aims to move people and cargo in small wheel-less pods in a vacuum tube at speeds that could exceed 600 miles per hour. Today’s swiftest rail travel, at top speeds less than half as fast, would become a quaint anachronism.

The company, which counts Sir Richard Branson’s Virgin Group as a minority investor, is one of several in the United States, Canada and other countries developing hyperloop technology. The concept was promoted by Elon Musk, of electric-car and private-rocket renown, and then offered by one of his companies as open-source technology available to all. It works by propelling pods using magnetic levitation through a low-pressure, near-vacuum tube. The low pressure minimizes friction and air resistance, greatly reducing the power needed. And because the pods travel in a tube, they’re not subject to shutdowns due to harsh weather, like snow or polar vortexes.