It takes roughly five-and-a-half hours to drive the 400 miles between Los Angeles and San Francisco. But in the future, the same trip could take around 30 minutes.

That’s the promise of the Hyperloop, the futuristic transportation system SpaceX and Tesla Motors founder Elon Musk says he will unveil a design for on August 12.

Will publish Hyperloop alpha design by Aug 12. Critical feedback for improvements would be much appreciated. — Elon Musk (@elonmusk) July 15, 2013

What is the Hyperloop, exactly? Musk has described his concept for a high-speed, tunnel-based tube system as “a cross between a Concorde, a rail gun, and an air hockey table,” but hasn’t publicly shared many other details since he first mentioned it a year ago. He has previously said the ideal system would be weather-proof, crash-proof, solar-powered, and at least twice as fast as a plane.

ET3, a Colorado-based company, is currently developing a similar technology for a high-speed tunnel system. Yahoo reports ET3 is planning a test run of three miles of prototype tubes by the end of 2013.

[Image: Flickr user OnInnovation]