powderjunkie beat me to it but winter tires just need to be all season with 3.5mm of tread depth and no ones checking anyways.
https://www2.gov.bc.ca/gov/content/t...t-winter-tires
It is true poor tires play into the winter driving problems here but I've watched people in trucks on flat ground spinning their tires and solution is to gun it harder. I'm not going to completely blame dumb winter drivers here but they definitely are to blame as it just creates more ice and there are so many vehicles that shouldn't be out. Busses and semis not making it up hills or over bridges though indicates its mostly just snow falling at 0C freezing and refreezing though. I think this time was particularly bad because snow really didn't start falling until about 3PM just as rush hour started and no one stayed home or went early.
On Vancouver Island as soon as there are signs of snow we shut down. Looking at traffic times probably ~50% didn't work or worked from home on Tuesday since it had snowed a few cm earlier that morning.