Wow that is quite the analysis... if elevators are so much better then why dont they use them in underground parking garages today? How do you resolve the issue of volume. If thousands of cars need to get into the tunnel at a certain point at the same time. Sleds seem crazy for the same reason. You will need thousands of them and they add a lot of complexity. I would say sleds would only be used for ICEv and a toll would be charged to use them, otherwise EVs would use FSD and receive signals from the tunnel's brain for control and navigation. I could be eating some crow, but it seems over complicated and thus expensive and prone for technical issues.
I think the answer could lie in the maglev elevator, or whatever you want to call it. It seems to have some ideas in common with the hyperloop in terms of magnetic acceleration and is easily scalable by adding more elevators to the same shaft.
MULTI - Rope-free elevator system - thyssenkrupp Elevator
it would be easy to have a lot of vehicles moving through a relatively small number of shafts and allow for high velocity movement.