International Driving License
While you can probably get away without having an international driving license, it is best to have all your bases covered and err on the side of caution.
Most police and rental car companies are satisfied with a license from the U.S., U.K., Australia and other western countries. However, it is possible to run across a functionary that will accept an international license only.
Driving on Your Own
For starters, Thais drive on the left hand side of the road. This makes it difficult for those coming from countries like the U.S. where people drive on the right.
Traffic laws are seldom enforced and the primary method of policing are road blocks set up to check to see if people are wearing their seat belts (or helmets for motorcyclists), whether the vehicle registration is up to date and other details.
Being stopped for speeding is rare but running red lights, passing on corners, passing when there is someone coming at you from the other direction and forcing people to move over - are all common occurrences.
A couple of unusual practices, for most westerners
- Flashing headlights on a vehicle coming at you mean "get out of the way - I'm coming".
- Emergency flashers at an intersection means the person is going straight through
Horns: A quick beep of the horn is okay to alert someone you are there. Laying on the horn aggressively just might get you in trouble.
While driving in the countryside isn't as fraught with challenges as driving in Bangkok, it does require ultra-defensive driving.
For more information see @ Driving in Bangkok.