WASHINGTON • Most people approve of driverless cars programmed to sacrifice their passengers to save others, but they will prefer not to buy such "utilitarian" vehicles themselves, a new survey revealed.
Driverless cars have the potential to benefit the world by eliminating up to 90 per cent of traffic accidents, but not all crashes will be avoided, and some crash scenarios will require them to make difficult ethical decisions, said the survey published in the United States journal Science.
"There are barriers to their wide adoption," study co-author Azim Shariff, an assistant professor of psychology at the University of Oregon, told reporters at a teleconference. "A number of those are technological barriers, but there are also psychological ones."
To investigate these psychological barriers, he and his colleagues conducted six online surveys of US residents between June and November last year, asking participants questions about how they would want their driverless cars to behave.
The researchers found that people generally take a utilitarian approach to safety ethics: They would prefer autonomous vehicles to minimise casualties in situations of extreme danger.
That would mean that, for example, having a car with one rider swerve off the road and crash to avoid a crowd of 10 pedestrians.
At the same time, the survey's respondents said that they would be much less likely to use a vehicle programmed that way.
Essentially, people want driverless cars that are as pedestrian- friendly as possible, except for the vehicles they would be riding in.
"To maximise safety, people want to live a world in which everybody owns driverless cars that minimise casualties," said study co-author Iyad Rahwan, an associate professor in the Massachusetts Institute of Technology Media Lab. "But they want their own car to protect them at all costs."
That would result in what the researchers called a "social dilemma", in which people could end up making conditions less safe for everyone by acting in their own self-interest.
"If everybody does that, then we would end up in a tragedy... whereby the cars will not minimise casualties," Mr Iyad added.
People were also strongly opposed to the idea of the govern- ment regulating driverless cars to ensure they would be programmed with utilitarian principles.
In the survey, respondents said they were only one-third as likely to purchase a vehicle regulated this way, as opposed to an unregulated vehicle, which could presumably be programmed in any fashion.
"For the time being, there seems to be no easy way to design algorithms that would reconcile moral values and personal self- interest," the researchers wrote in their paper.
"But public opinion and social pressure may very well shift as this conversation progresses."