Elon Musk, head of Tesla Motors and SpaceX, plans to reveal his design next week for a “Hyperloop,” a method of transportation along the California coast that would take passengers from LA to San Francisco in 30 minutes. Musk announced the release date for the plans last month and mentioned them again during a Tesla Motors earnings call Tuesday, Gizmodo reported.

The Hyperloop was first mentioned in Businessweek in 2012, where Musk described a “fifth mode of transportation” that has none of the disadvantages of public or private modes like the cars, planes, trains, or boats that we use now—it shouldn’t crash or have downtime, and it would be solar-powered.

The Hyperloop would not only be irrationally fast, taking about a third of the time a plane does to go from one destination to the other, it would “leave when you arrive,” meaning no appointment-style waits like there are for public transportation. Musk also claimed the Hyperloop would cost a tenth of the $60 billion that the state of California is paying to build a bullet train running the same route that takes five times as long to complete the trip.

Musk tweeted in July that he would release an “alpha design” for the Hyperloop on August 12, which he intends to be open-source, and that he would be looking for feedback. But on the earnings call Tuesday, Musk said he doesn’t think he has time to develop the Hyperloop beyond an idea. “I have no plans to execute it,” Musk said, but he still plans to put the information out there for others to improve upon.