In the video, we see cars driving on surface streets. The camera follows a Tesla that pulls off to the side of the road and onto a platform that lowers it underground. Below the surface, the car joins a number of others being carried through tunnels on mobile platform at speeds of up to 124 miles per hour. We see a vast network of underground paths that look like their own highway system.
Eventually, we see the car re-emerge onto a surface street. It pulls off its platform into traffic, allowing another car to takes its place and head into the tunnel system. The video also shows what appear to be autonomous shuttles operating on the roads and using the tunnel network.
Musk is not one to shy away from grand visions, and this video from The Boring Company is just another example of that. It's an interesting thought exercise about the future, and one we'll likely hear more details about soon. Check out the video above.