As you approach a rise in the road, heading south, a school bus appears, driving north, one driven by a human, and it veers sharply toward you. There is no time to stop safely, and no time for you to take control of the car.
Does the car:
A. Swerve sharply into the trees, possibly killing you but possibly saving the bus and its occupants?
B. Perform a sharp evasive maneuver around the bus and into the oncoming lane, possibly saving you, but sending the bus and its driver swerving into the trees, killing her and some of the children on board?
C. Hit the bus, possibly killing you as well as the driver and kids on the bus?
In everyday driving, such no-win choices may be exceedingly rare but, when they happen, what should a self-driving car — programmed in advance — do? Or in any situation — even a less dire one — where a moral snap judgment must be made?
Few people seem to be in a hurry to take on these questions, at least publicly.
It’s unaddressed, for example, in legislation moving through Congress that could result in tens of thousands of autonomous vehicles being put on the roads. In new guidance for automakers by the U.S. Department of Transportation, it is consigned to a footnote that says only that ethical considerations are "important" and links to a brief acknowledgement that "no consensus around acceptable ethical decision-making" has been reached.
Whether the technology in self-driving cars is superhuman or not, there is evidence that people are worried about the choices self-driving cars will be programmed to take.
Last year, for instance, a Daimler executive set off a wave of criticism when he was quoted as saying its autonomous vehicles would prioritize the lives of its passengers over anyone outside the car. The company later insisted he’d been misquoted, since it would be illegal “to make a decision in favor of one person and against another.”
Last month, Sebastian Thrun, who founded Google’s self-driving car initiative, told Bloomberg that the cars will be designed to avoid accidents, but that “If it happens where there is a situation where a car couldn’t escape, it’ll go for the smaller thing.”