I think train surfing would be a great thing to be able to do. If you train surf you don't have to pay for tickets, but it comes with a risk, if you get spotted or fall of the train that you can get arrested, major injuries or even death.

I've heard from another post that there wont be any air vehicles exept if a dlc to another island is made.

I know, but standing on a moving train is still dangerous even if it's computer controlled. At least i think so.

Ok, i didnt expect that.