Why Google's self-driving car is not ready for prime time, and may not be for a while
Weather: "Among other unsolved problems, Google has yet to drive in snow, and Urmson says safety concerns preclude testing during heavy rains."
Road obstacles: "The car’s sensors can’t tell if a road obstacle is a rock or a crumpled piece of paper, so the car will try to drive around either. Urmson also says the car can’t detect potholes or spot an uncovered manhole if it isn’t coned off."
Unmapped areas: "Google says that its cars can identify almost all unmapped stop signs, and would remain safe if they miss a sign because the vehicles are always looking out for traffic, pedestrians and other obstacles.Alberto Broggi, a professor studying autonomous driving at Italy’s Università di Parma, says he worries about how a map-dependent system like Google’s will respond if a route has seen changes. . . . Urmson said his team is still working to prevent them from being blinded when the sun is directly behind a light."
Construction: "Despite progress handling road crews, “I could construct a construction zone that could befuddle the car,” Urmson says."
Pedestrians: "Pedestrians are detected simply as moving, column-shaped blurs of pixels—meaning, Urmson agrees, that the car wouldn’t be able to spot a police officer at the side of the road frantically waving for traffic to stop."
Google is talking about solving these problems within five years, but many don't believe these problems will be solved anytime soon: "But researchers say the unsolved problems will become increasingly difficult. For example, John Leonard, an MIT expert on autonomous driving, says he wonders about scenarios that may be beyond the capabilities of current sensors, such as making a left turn into a high-speed stream of oncoming traffic."