This is almost certainly a project to prove parts of their technology, which is part of Musk's greater ambition, and not an "optimal" solution to this particula

This is almost certainly a project to prove parts of their technology, which is part of Musk's greater ambition, and not an "optimal" solution to this particular problem. I think his end-goal here is to create a series of tunnels with skates for cars which his electric cars can drive up to, and then be ferried to their end destination at high speed without traffic.