Would it be possible to have a memory drive? Install a software that recognizes a trip from A to B ie: daily commutes or routes driven frequently. Before you start a trip from A to B you "set"" memory" and begin your drive and the car memorizes the trip. That could be utilized when there is heavy snow or dirt, or roads that do not have road markings. Recognizing stop signs,other road signs that have heavy snow coverage/damage and the car will still stop 2nd to the "memory software" If you complete the first trip from A to B you save the trip and the 2nd time you go the car will do the driving for you in conjunction with the autopilot.