It's by treaty, so ameritards can drive in the other countries with their own cars/trucks. More worryingly, several sandnigger countries are part of the same treaty, but since few of them can be bothered to transport their cars to the continent you don't see them all that often, outside of supercars. Also, there is another treaty governing IDPs (international driving permits) which mean you can rent cars in most other countries, even if they drive on the wrong side of the road, etc. and drive without further instruction or testing. Notably China is not part of that treaty, so self-drive for foreigners in China is next to impossible. Anyway you can't legislate terrible driving into good driving. If you want good drivers you need race tracks and all terrain parks where people can get practice rather than having them use "road experience" to learn.