In May 2013, Musk likened the Hyperloop to a "cross between a Concorde and a railgun and an air hockey table,", he also believes it could work either below or above ground.
In May 2013, Musk likened the Hyperloop to a "cross between a Concorde and a railgun and an air hockey table," while noting that it has no need for rails. He believes it could work either below or above ground.