The IDP (International Driving Permit) is valid under international law, authorized by the UN (United Nations), and allows the holder to lawfully travel in any country which was a signatory or who ratified the treaty. The US became a signatory to the 1949 Convention on Road Traffic. When using the permit you are obligated to follow all the traffic laws of the jurisdiction you are traveling in. With the IDP, an officer will generally treat you better because you are not licensed in his jurisdiction and therefore he has less control over you. Cost of IDP is $200 and it's valid for 4 years.