Traveling by Car
U.S. citizens do not need to obtain an international driver’s license to drive in Canada. Your valid U.S. license is good for trips in Canada as long as you are a visitor and are actually resident in the U.S. Should you wish information on provincial traffic laws, please contact the Department of Transport, Motor Vehicle Division of the particular province you wish to visit. You may also contact the American Automobile Association (AAA), web site at http://www.aaa.com, or the Canadian Automobile Association (CAA), web site http://www.caa.ca, if you are a member. The CAA covers AAA members while traveling in Canada. Be sure to carry proof of your car insurance.
Please note, the island of Montréal prohibits right turns on red, while the rest of Canada and the rest of Québec, allow it.
Excepted from: http://travel.state.gov/travel/tips/regional/regional_1170.html