They don't operate in snow now, but everybody was like "This is great, but it doesn't work in the rain!" this time last year. I've now taken many flawless rides in outright downpours in SF. It might take a year or two, but I have no doubt snow will be something that is a non-issue in the near future.
Sensing tech has to improve to get through the noise. As far as I'm aware, you can't see a yellow line or white line on a highway if it's covered in dirty snow.
We could also rework our roadways to include better sensing design and tech (passive or active!), but we are a ways out still from willingness to pay for that.
Do what humans do and drive without lines while trying to stay to one side of the road. This doesn’t seem like a major problem to self driving snow cars. More like, how do you deal with other drivers who are RWD with summer tires and are fish tailing all over the place.
If the sensors are up for it... Mountain roads covered in snow pack are a white blur, especially in certain light. Best bets for actually knowing where the road is might be previous tracks. I've dipped a wheel in a ditch more than once, not from carelessness, but snow drift obscuring the road... A road that I drive 500 times a year
