With the changing technology around winter tires, there has been a bit of confusion around this question. Because of that, the Ministry of Transportation and Infrastructure is going to assess the existing definition of “winter tires and chains” as part of the highway speed and safety review you may have heard about.

In the meantime, there are six things you need to know now.

1.   What’s Recommended: The RCMP and the ministry agree that for winter driving conditions a tire with a mountain/snowflake symbol is the best choice. We encourage drivers to choose the best tires possible, and to ensure the tires are in good condition, with good treads, and by that we mean tires having a minimum tread depth of 3.5 mm.
2.   What’s Legal: The legislation as written accommodates M + S tires. B.C. RCMP will continue with past practice of allowing either tires with a snowflake symbol or a mud and snow designation on highways where winter tires are required, as long as they are in good condition, with good treads (worth repeating).
3.   Where Must I Have Winter Tires: We are only talking about the highways where the signage is – on the mountain passes in B.C. and in areas subject to winter conditions including the interior and north. We are not talking about drivers in the city limits. A map of the designated highways where motorists must have winter tires or chains can be found at: www.th.gov.bc.ca/SeasonalDriving/winter_chains.html
4.   What if the Weather is Really Bad: In severe winter weather, police officers may turn vehicles around, regardless of the type of winter tire they are using, if they feel the tires are unsafe for the conditions and may be putting the driver at risk.
5.   Where do I Get More Information About Winter Tires: Contact your tire manufacturer or local tire shop to discuss your tire needs and the best choice for safe winter driving.
6.   Does this Affect Everyone: Since more than 60 per cent of all B.C. drivers travel the province in places where snow rarely falls, the ministry is not considering requiring all drivers to equip their vehicles with winter tires.

Source:

http://tranbc.ca/2014/10/01/shift-into-winter-the-inside-scoop-on-winter-tires/