Elon Musk has plans — or maybe it’s just an idea — for a brand new form of transportation.

He calls it the “Hyperloop,” and its a way to travel long distances quickly.

At the D11 conference Musk danced around the topic a bit. He didn’t want to talk about the Hyperloop because he wanted the focus of his interview to be Tesla.

The most he would say is that the Hyperloop is a “cross between a Concorde, a railgun and an air hockey table.”