A supersonic "Hyperloop" transport concept to link Los Angeles and San Francisco in 30 minutes has been unveiled.
US entrepreneur Elon Musk, founder of SpaceX, Telsa Motors and Paypal, revealed his vision for a transport system of solar-powered network of crash-proof capsules in a blog post.
The Hyperloop, which Musk previously described as a cross between a Concorde, rail gun and air-hockey table, would cost an estimated $6 billion to build.
Construction for the new mode of transport would take 7 to 10 years.
According to the 57-page design plan, As many as 28 passengers could ride in each pod and the system could even transport vehicles.
The proposal was met with much interest but not everyone is convinced the project is a good idea.
Jim Powell, a co-inventor of the bullet train, said the system would be highly vulnerable to a terrorist attack or accident.
After taking an initial look at Musk's specifications, he told Reuters: "All a terrorist driving along the highway has to do is pull over, toss a net of explosives at it, and then everyone in the tube dies".