"This system is designed to be more like a highway and a bunch of off-ramps and loops connecting to the highway, kind of like cars," Musk said. "Almost like an autonomous underground, multi-level car system… that costs a dollar."
Musk is also the boss of electric automaker Tesla and space exploration firm SpaceX.
He assured people in the audience that the project would not be noisy and would reduce traffic significantly.
"Compared to a flying car, you don't have to worry about bad weather, you can't see it, hear it feel it, you're not dividing communities with lanes and we think we can make this really fun," Musk said.
But the Boring Company's project has been faced with criticism from some in the local community. Two neighborhood groups have targeted the approval of a 2.7-mile tunnel planned by the firm with legal challenges.
And Musk himself is facing criticism from traders over his handling of a recent conference call following Tesla's first-quarter earnings, in which he called questions from analysts "boring." Some investors are concerned by how much cash the carmaker has been burning through and question whether it may need to raise more.
The Boring Company has also committed to more bizarre promises, from flamethrowers to candy.