2 or 4 Winter Tires?

I began driving my own car in the mid-fifties and I always used winter tires on the rear only during the winter months. Based on about thirty years of experience, I feel that I am quite capable of managing winter driving with the traction arrangement I had for rear drive in the past. However, I am not interested in contravening any legislated law or regulation. Is there a law that requires me to have winter tires on all 4 wheels of my new rear wheel drive only pickup?
Based on my experience as a collision analyst, I can tell you that any vehicle will steer more predictably if the traction at each wheel is the same. Whether you choose to use four all season tires or four winter tires is up to you, but operating with two all season tires on one end and two winter tires on the other is an invitation to problems. Mixing tire types will affect both steering and braking.
Having different sets of tires on front and rear axles may cause one end of the vehicle to lose traction before the other in a turn. Depending on the conditions, this could include having four winter tires or four all season tires where the pairs have different tread patterns or traction characteristics.
In terms of braking, four all season tires may be good, two of each may be better, but the best is still four matched winter tires. Braking distances will also differ if the two winter tires of a mixed set are on the front instead of on the rear.
There are two rules in British Columbia regarding four matched tires on vehicles with four wheels. If the front tires are studded, the rear tires must be also, and tire types may not be mixed. All 4 must be radial ply or all 4 must be bias ply.
Reference Link: http://www.drivesmartbc.ca/equipment/two-or-four-winter-tires