About EJ MTB

It wont work.

EJ MTB
Other
United Kingdom

This will not work because of these reasons, If there is a breakdown inside the tube the breakdown will cause a big traffic jam in the tunnel and it will be difficult to remove the car if needed, this is the same for a car crash.

Also if there is a crash the heat underground will eventually if not helped quick enough, there shall be a possibility of death. I may be wrong about all this but in London a tube broke down a few years back and the heat nearly killed the occupants of the underground train.