To be awarded with this achievement you should go to the "
world map" tab in main menu and see how much % do you have already. If you don't have enough, you must discover
new roads and cities (
undiscovered are shown on the map in gray, discovered are yellow). You only need to ride a road once to mark it as discovered.
I suggest using this mod#emanuele_mauri | iPLAY4FUN | Live | myBlog