Device

I have been thinking about the world needs like a non-contaminating transport, or future more ideas for natural energy. So I thought of a transport, a very modern transport, public transport that has a round form that with a metal thing that push it, so it will roll on metal rail’s as the train ones. People will roll but if the round transport have two stages one at the outside that rolls and another one that stays still. When it’s going to stop in a place a door with to arms will trap it. 
 * My Great Idea: **