When I was there this past summer, I was surprised to see how many people were out walking and riding with hi-vis. I saw so many that I thought maybe it was a legal obligation. But with the conditions as bad as they were in the summer, I can imagine how much worse it must be in the winter. In that case I would definitely be wearing hi-vis whether or not it was required. But it does suck be told you must wear it even if you don't wanna.