The blueprint for a "Hyperloop" transport system capable of reaching speeds of 760mph has been unveiled.
The system would enable people to travel 400 miles from Los Angeles to San Francisco in 30 minutes at near-supersonic speeds.
It is designed to be self-powering, uses magnets and fans to shoot capsules carrying passengers on a cushion of air through pressurised tubes.
The revolutionary invention is the brainchild of billionaire entrepreneur Elon Musk, who has called the system a cross between a "Concorde, a railgun, and an air hockey table".
The founder of electric car maker Tesla Motors and private space exploration firm SpaceX, released 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.
He said the system was capable of speeds up to 760mph (1,220kph) an hour, and would best work between cities closer than 900 miles.
The estimated cost of connecting Los Angeles and San Francisco is $6bn (£3.9bn), which could translate to a fare of about $20 (£13) for a one-way ticket.
He has no plans to build the system immediately, but said he wanted to reveal a detailed design of the concept to allow others to brainstorm ideas and improve on his vision.
The 42-year-old, who was born in South Africa but is a US citizen, is also the head of SolarCity, a company which makes solar panels for homes and businesses.
He also has a foundation that focuses on education, clean energy and child health.
He banked his first millions when he sold Zip2 to US computer maker Compaq for more than $300m (£194m) in 1999.
His next company, X.com eventually merged with PayPal, the online payments firm bought by internet auction giant eBay in 2002.
By (Sky News)