From Henry Blodget’s new Business Insider piece about Google’s self-driving cars, a passage about the obstacles the company has to overcome to perfect its auto software:

“The first challenge is driving in snow.

When snow is on the road, the cars often have a tough time ‘seeing’ the lane markers and other cues that they use to stay correctly positioned on the road. It will be interesting to see how the Google team sorts that one out.

A second challenge, apparently, is when the car encounters a change in a road that is not yet reflected in its onboard ‘map.’ In those situations, the car can presumably get lost, just the way a human can.

A third challenge is driving through construction zones, accident zones, or other situations in which a human is directing traffic with hand signals. The cars are excellent at observing stop signs, traffic lights, speed limits, the behavior of other cars, and other common cues that human drivers use to figure out how fast to go and where and when to turn. But when a human is directing traffic with hand signals–and especially when these hand signals conflict with a traffic light or stop sign–the cars get confused.”