I'm not sure if this is happening in the U.S. but CAA has warned us here in Canada that while you may not "need" an IDP...International Driver's Permit...there have been some cases where, while in a foreign country,,that did not require an IDP..only a valid Canadian Lic... the Canadian tourist has gotten into a collision...the insurance company refused to pay the claim because..as they said..their insured did NOT have a valid driver's lic. for the country they were visiting. An IDP is supposed to be good in any country in the world and in Canada you can get one at CAA for 30 something dollars and the permit is good for one year. To protect yourself from your insurer from trying to wiggle out of a claim on a technicality I think it's worth the small amount of money for the IDP.