On August 12, 2013, Musk unveiled a concept for a high-speed transportation system incorporating reduced-pressure tubes in which pressurized capsules ride on an air cushion driven by linear induction motors and air compressors. - Hyperloop is a proposed mode of passenger and freight transportation that propels a pod-like vehicle through a near-vacuum tube at more than airline speed. This version was published on the SpaceX website, which describes the design, and function of the system. The pods would accelerate to cruising speed gradually using a linear electric motor and glide above their track using passive magnetic levitation or air bearings. The tubes could also go above ground on columns or underground, eliminating the dangers of grade crossings.
The concept of high-speed travel in tubes has been around for decades, but there has been a resurgence in interest in pneumatic tube transportation systems since the concept was reintroduced, by Elon Musk in 2012
The outline of the original Hyperloop concept was made public by the release of a preliminary design document in August 2013, which included a suggested route running from the Los Angeles region to the San Francisco Bay Area, paralleling the Interstate 5 corridor for most of its length. Preliminary analysis indicated that such a route might obtain an expected journey time of 35 minutes, meaning that passengers would traverse the 350-mile (560 km) route at an average speed of around 600 mph (970 km/h), with a top speed of 760 mph (1,200 km/h). Preliminary cost estimates for the LA–SF suggested route were included in the white paper—US$6 billion for a passenger-only version, and US$7.5 billion for a somewhat larger-diameter version transporting passengers and vehicles —although transportation analysts had doubts that the system could be constructed on that budget; some analysts claimed that the Hyperloop would be several billion dollars over budget due to construction, development and operation costs.
To that end, a few companies have been formed, and several interdisciplinary student-led teams are working to advance the technology. Hyperloop One of Los Angeles is the only company currently building a full-system and full-scale Hyperloop prototype and is expected to run the first test in early 2017, having demonstrated its propulsion system using a custom-designed bogie on a 1 km track in May 2016. SpaceX built an approximately 1-mile-long (1.6 km) subscale track for its pod design competition at its headquarters in Hawthorne, California.