The filing gives permission to dig a vertical shaft in a residential garage that would connect to an underground test tunnel. That tunnel would lead back to SpaceX's headquarters. Cars could be lowered down from the garage on an elevator inside the shaft, then loaded onto an electric "skate" to be transported at high speed.
Traffic reduction is one of the Boring Company's goals. A vast network of these things would mean people would be driving far fewer miles in their cars, because it would only require a short trip once they get out of the underground tunnel.
It's smart to maintain a fair bit of skepticism on this one. The cost to install such a system in a personal home would surely be astronomical. But then again, prices for everything are astronomical around Los Angeles and San Francisco. There are clearly still a lot of hurdles for Musk and his company, because large-scale application of the the envisioned tunnel system would be a huge task. This new addition to the project is interesting, though, and would probably be happily accepted in the unbearable traffic hellscape that Southern California is.
First Boring Brick store opening in ~2 months. Only 10 cents a brick! Rated for California seismic loads.— Elon Musk (@elonmusk) September 13, 2018
Elon Musk also tweeted that the Boring Company would open a brick store within the coming months, selling bricks at $0.10 apiece, or free to affordable housing projects. The Boring Company's FAQ page states that the company is "investigating technologies that will recycle the earth [bored from tunnels] into useful bricks to be used to build structures."