Last summer, we reported that Google's self-driving car prototypes didn't need windshield wipers because human operators don't need to see out. As it turns out, Google's cars do need windshield wipers, but not on the windshield. Google developed tiny wipers for the roof-mounted sensors on its prototype self-driving cars, according to .
These tiny, precious wipers are designed to ensure Google's laser sensors have a good view of the road in inclement weather. Google says cameras and lasers, like human eyes, have a more difficult time "seeing" in the rain, but radars have no such trouble. The lasers and cameras have to be "taught" to see through raindrops and exhaust clouds.
Google also says its cars can measure the severity of the rain and change their driving style accordingly, automatically stopping if the conditions are too bad.
Currently, Google is working on acquiring more testing data in rain and snow, its cars having logged most of their miles in relatively sunny Mountian View, Calif. and Austin, Texas.
The lack of windshield wipers was used to illustrate how vastly self-driving cars will be to their conventional counterparts, but it turns out that they're not quite so different.