"AS FAST AS LIGHTNING"

The Hyperloop is a theoretical high-speed transportation system. The Hyperloop  put forward by businessperson (Elon  Musk), incorporating reduced-pressure tubes in which pressurized capsules ride on a cushion(1) of air that is driven by a grouping of linear induction motors and air compressors. The theoretical road runs from the Los Angeles region to the San Francisco Bay Area, paralleling the Interstate 5corridor for most of its length, with an expected journey time of 35 minutes, meaning that passengers would traverse the 354-mile (570 km) road at an average speed of around 598 mph (962 km/h), with a top speed of 760 mph (1,220 km/h).

A opening design document was made public in August 2013, which included an estimate of a US$6 billion construction cost for a passenger-only version of the system, while a version allowing for transportation of both passengers and vehicles was estimated at US$7.5 billion. The cost projections have been questioned by transportation engineers and others, who contend(2) that the sum is unrealistically(3) low given the scale of construction required and the level of unconfirmed technology involved. The technological and economic feasibility of the idea is unproven and a subject of significant debate.

1/cushion: a bag made of cloth, plastic or leather which is filled with soft material, often has an attractive cover, and is used especially on chairs for sitting or leaning on 2/contend: to state that something is true or is a fact 3/unrealistically : not fair or acceptable