Elon Musk is not planning to to develop his Hyperloop mass transit idea with a company of his own. Instead, he is encouraging others to develop it. Today SpaceX announced that a short test track will be built near the company’s headquarters in Hawthorne, California, which will be used for
an open competition, geared towards university students and independent engineering teams, to design and build the best Hyperloop pod. To support this competition, SpaceX will construct a one-mile [1.61 km] test track adjacent to our Hawthorne, California headquarters. Teams will be able to test their human-scale pods during a competition weekend at the track, currently targeted for June 2016. The knowledge gained here will continue to be open-sourced.
The details of the competition are described in SpaceX Hyperloop Pod Competition (pdf).