Guys, guys, hear me out. I have a crazy idea.

What if we use special cars only for the tunnel with some kind of ride sharing system? and then we put the cars on rails? This keeps them on track and also the rolling friction is much lower.

Also, we could continuously charge the battery of the car if we have some kind of wire going alongside the tunnel and a slip contact.

Actually we could make the cars much bigger as well, so they can hold more people.

Get me patent lawyer.