The robot will be far, far better than humans at driving in such conditions. Modern cars already help out as best they can with monitoring slippage, temperature sensing, running in higher gears, monitoring road gradient and rate of change thereof, running wheels at different settings, and all the rest of it; if the meatbag would just sit in the back and let the robot drive everything would be much safer.
The indicator will say :"It's snowing meatbag, please wait until the road is warm and dry, or give me the wheel".