Researchers asked more than 3,200 adults in the US and five other countries (India, China, Japan, Great Britain and Australia) what kinds of activities - many of which could cause motion sickness - they would do in a fully self-driving vehicle.
More than a third of Americans said they would do things that increase the likelihood and severity of motion sickness - reading, texting, watching movies or television, playing games or working.
About 6-12 per cent of American adults riding in fully self-driving vehicles would be expected to experience moderate or severe motion sickness at some time, researchers said.
Similar percentages would also apply to residents in India, China, Japan, Great Britain and Australia, they said.
"Motion sickness is expected to be more of an issue in self-driving vehicles than in conventional vehicles," Michael Sivak of the University of Michigan Transportation Research Institute said.
"However, the frequency and severity of motion sickness is influenced by the activity that one would be involved in instead of driving," Sivak said.
Researchers found that more than 60 per cent of Americans would watch the road, talk on the phone or sleep while riding in a self-driving vehicle - activities that would not necessarily lead to motion sickness.
Sivak and researcher Brandon Schoettle suggest that manufacturers can design self-driving vehicles to lessen the likelihood of motion sickness: maximise the visual field with large, transparent windows; mount transparent video and work displays that require passengers to face forward; and eliminate swivel seats, restrict head motion and install fully reclining seats.
