According to the California Department of Motor Vehicles site 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.
If you take a job here or become a resident, you must get a California driver license within 10 days. Residency is established by voting in a California election, paying resident tuition, filing for a homeowner's property tax exemption, or any other privilege or benefit not ordinarily extended to nonresidents.
If you have a license from another country, you will be required to take a driving test. The CA DMV states that if you are over 18 and are applying for an original driver's license (which we take to mean your first driver's license) you will need to pass a traffic laws and sign test. There are 36 questions on the test. You have three chances to pass.
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[Let CarInsurance.com help you find affordable auto insurance now.] To make certain we are correct on our understanding that a written test will not be required if this is not your first driver's license check with the CA DMV. This state agency should also be able to answer any other questions you have about how to change over your Indian driver's license for one issued from California.
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