Elon Musk has unveiled a near-supersonic transport concept to link Los Angeles and San Francisco, cutting the 610km journey to less than half an hour.
The blueprints reveal how the US-based billionaire wants to use magnets and fans to fire passenger-carrying capsules floating on a cushion of air through pressurised tubes. The plans were released as part a 57-page document outlining the project.
"Short of figuring out real teleportation, which would of course be awesome ... the only option for super-fast travel is to build a tube over or under the ground that contains a special environment," he wrote.
The SpaceX, Tesla and Paypal founder said the capsules would travel at speeds of up 1220km/h or nearly the speed of sound. Musk claimed the solar-powered shuttle would be a quicker, safer, cheaper, and more efficient mode of transport between Los Angeles and San Francisco than the high-speed train line that is currently being built.
The pods could arrive every 30 seconds and even accommodate cars onboard.
Last week Musk described the concept as a cross between a "Concorde, a railgun, and an air hockey table".
He said on a conference call that passengers in the cabins would experience a little bit more than the force of gravity and compared the experience to being on an aeroplane as opposed to a rollercoaster.
He said the concept would work best between destinations less than 1,000km, adding that anything beyond that would be more suited to supersonic air travel.
In order to avoid minimal disputes over land, Musk envisions building the project on an elevated platform alongside an existing Californian motorway. He said the structure holding it up would be designed to withstand earthquakes.
Musk estimated that linking the two Californian cities in this way would cost $6bn (£3.9bn) and said fares could be in the region of about $20 (£13) for a one-way ticket.
Musk has said he is currently too busy to develop the project himself and is therefore making it "open source" so that anyone can improve it, or try to create it.