VIDEO - How to Determine if it is Safe to Pass
The video explains when not to pass, when it's okay to pass, and how to determine if you have time to pass safely. There is one fault with it as it shows passing on the right after crossing over a solid white line. This pass would be illegal in British Columbia. Otherwise, the advice is worthwhile.

The province of British Columbia has not yet mandated that only true winter tread tires be used during the winter months on our highways. If you pass a sign requiring the use of winter tires between October 1 and April 30 each year, your vehicle must be properly equipped.