What will happen if it stars snowing? The self driving cars will be stuck on the roads?(I mean in the future where the passenger can't drive the car back home)

Following the line is too basic for a self driving car, I remember some students having small toys programmed to drive toy roads by following the lines, and that was more then 10 years ago.

Tesla should have detailed maps of this big roads, so maybe when the maps and what the car detects do not match it should be less confident, the collision detection should be extra sensitive, the driver should be alarmed, the car should slow down, if they have problems on this big roads then they need a new kind of hardware and software to navigate any medium road.