[agildehaus]

The 3 lane to 2 lane problem is solved already. These cars follow a centimeter-accurate 3D map that has the lanes precisely defined (as well as acceptable speeds, location of stoplights, etc).

The Google car knows the lane change is approaching long before it shows up on any sensor.

[Swizec]

This isn't about a lane change approaching. This is about people disregarding the concept of lanes when there's fresh snow on the ground because they have no idea where the lanes are.