De USA.gov , parece que depende muito de quais estados você planeja dirigir:
If you are a visitor from outside the United States and Canada who plans to drive in the U.S., check with the motor vehicle department of each state you will drive in for its requirements. Some of the states will require an International Driving Permit (IDP) in addition to a valid license from your own country.
Isso é um pouco vago e não esclarece a questão da linguagem. Felizmente, justlanded.com aborda isso:
Tourists may drive in the US for up to a year with a foreign driving licence, provided the issuing country is party to the 1949 Geneva Convention on Road Traffic (see art. 1 and art. 25 para. 1) or to the Convention on the Regulation of Inter-American Automotive Traffic (Washington, 1943); most countries are contracting parties.
(Boas notícias, A França faz parte da convenção de 1949 !)
Eles continuam dizendo:
If your foreign licence doesn’t contain a photograph or is written in a language other than English, it’s wise (but not mandatory) to obtain an International Driver’s Permit (IDP). Always carry your foreign licence as well as your IDP. Without an IDP it may be necessary to obtain a certified English translation of your foreign driving licence, usually obtainable from your country’s embassy in the US.
Espero que ajude a esclarecer as coisas.