hyperloop . Then the serial CEO and iconoclast created the Boring Company to dig networks of urban tunnels that bypass traffic using high-speed electric "skates" shooting cars around the underground. Now he says both new forms of transportation will prioritize mass transit, specifically pedestrians and cyclists, over cars. Previously, the Boring Company showed off renderings of a system that lowers individual cars from the street level down into an underground high-speed network, but now Musk, who's also CEO of Tesla and SpaceX, says the carless will get first priority. Watch this: Elon Musk offers new vision for Boring Company 01:14 "Will still transport cars, but only after all personalized mass transit needs are met," Musk tweeted Friday. "It's a matter of courtesy & fairness. If someone can't afford a car, they should go first." In December, Musk got into a war of words on Twitter with public transit policy expert Jarrett Walker. Walker accused Musk of harboring a "hatred of sharing space with strangers" and Musk responded, calling Walker a "sanctimonious idiot." Musk now wants to reiterate that he's a fan of public transit by basically reinventing the city bus to go faster than ever before. "I guess you could say it's a 150 mph, underground, autonomous, electric bus that automatically switches between tunnels and lifts. So, yes, a bus," he wrote on Twitter. Better video coming soon, but it would look a bit like this: pic.twitter.com/C0iJPi8b4U