Quebec drivers are required by law to fit passenger vehicles with four winter tires by Dec. 15 and keep them on until March 15, or risk fines of 200 to 300 Canadian dollars. A study by the Quebec Ministry of Transport says all winter accidents fell by 17 percent compared with the five winters preceding the enactment of the 2008 law. Accidents causing deaths or serious injuries fell by 36 percent. The specialized tires are mandatory for all passenger cars and taxis registered in the province, as well as rental cars from Quebec locations.