미국과는 협정이 체결이 안 되어있지만 각 주별로 인정을 해 줍니다. 한국면허증과 국제면허증 둘 다 있어야 합니다. 실제 효력이 있는 것은 한국면허증이고 국제면허증은 일종의 번역입니다. 렌터카할 때 한국면허+국제면허면 됩니다.

주마다 틀리지만, bestway님 말씀처럼 CA는 방문자에게 한국면허증으로 운전을 인정해 줍니다.
(단, 반드시 한국면허증이 있어야 합니다.)

<a href=http://www.dmv.ca.gov/dl/dl_info.htm#2500
target=_blank>http://www.dmv.ca.gov/dl/dl_info.htm#2500

If you are a visitor in California over 18 and have a valid driver license from your home state or country, you may drive in this state without getting a California driver license as long as your home state license remains valid.

http://www.dmv.ca.gov/dl/dl_info.htm#international
The State of California does not recognize an International Driving Permit (IDP) as a valid driver license. California does recognize a valid driver license that is issued by a foreign jurisdiction (country, state, territory) of which the license holder is a resident.

The IDP is only a translation of information contained on a person’s foreign driver license and is not required to operate a motor vehicle in California. Citations issued to a person in California who has an IDP, but does not have a California driver license will be placed on the Department of Motor Vehicle database.

The IDP is also called an International Driver License, International License, etc.

렌트하실 때 추가로 운전하실 분 additional driver로 등록해야만 만약에 사태에 보상 받을 수 있습니다. (추가 부담)