Comment by reubenswartz

By the time you could conceivably build some of these tunnels, the Teslas and most other cars will be at least somewhat self-driving. (Since you're in tunnels, the problem gets a lot simpler, with on/off the real tricky parts.

I would have thought you'd say where you wanted to go, and if you had enough battery to get there, the car would just drive itself in the tunnel, eliminating the need for a whole other wheeled, motorized sled to move a wheeled, motorized vehicle.