DETROIT — For decades, automakers have studied what happens to people inside cars when the vehicles crash with an alert driver behind the wheel.
But engineers are only beginning to understand how bodies might be flung around inside autonomous vehicles when the "driver" is checking email, watching TV or even sleeping.
The question matters because occupants of self-driving cars might need a host of new safety technologies to protect them.
Drivers and riders might not brace for impact or even be facing forward at all, if futuristic visions for self-driving lounge spaces come to fruition.
Toyota Motor Corp. just completed its biggest in-depth study of the matter, chronicling the body movements of people in simulated near crashes of autonomous vehicles.
Its conclusion: A lot more research is needed.
"We want to be able to offer improved technologies, based on what new postures might be present in a vehicle equipped with automated crash avoidance technologies," said Jason Hallman, the principal safety and crashworthiness engineer who led the one-year study.
"All we have is this hypothesis that maybe the posture would be different. We can't make any new technology or new design without knowing conclusively what we should be designing to," Hallman said. "But we don't know what that posture might be."
Toyota ran the study on 87 volunteers at the University of Michigan's Mcity autonomous driving testing ground in Ann Arbor from 2016 through 2017. It will release full findings in October at a conference of the Association for the Advancement of Automotive Medicine.