Riding as a passenger in a car gives up to one-third of Americans motion sickness, a National Institutes of Health statistic that could increase if more people are riding rather than driving in the future age of autonomous vehicles. The University of Michigan in Ann Arbor is investigating whether this will be a potential problem.
In a vehicle, motion sickness car tends to occur when riding rather than driving, and can be more pronounced when engaged in something other than looking out the window, reading, or using a handheld device, for example.
“One of the great promises of autonomous vehicles — to give us back time by freeing us from driving — is at risk if we can’t solve the motion sickness problem,” says Monica Jones, an assistant research scientist in the Biosciences Group at the University of Michigan Transportation Research Institute (UMTRI). “If it’s not mitigated in some way, motion sickness may affect people’s willingness to adopt driverless cars.”
Jones is the lead investigator on a research project to identify and quantify motion sickness in passenger vehicles.
The research team has developed a repeatable and reliable testing protocol for evaluating specific real-world driving maneuvers and passenger activities that make people carsick. No such methodology existed before. The study is the first to conduct a large-scale comparison of reading task performance and urban acceleration levels on motion sickness response in a passenger vehicle. A white paper about the protocol was published Mcity.
“Very few studies have been conducted in cars,” Jones explains. “A lot of the work has been done for sea and air transportation modes, performed in driving simulators or on motion platforms. These results are not translating very well to road vehicles.”
Beyond that, previous research hasn’t asked the right questions.
“A lot of scales that exist in the literature are based on nausea,” Jones said. “If we design to a vomiting response, we have really missed the mark on autonomous vehicles. We need to target comfort levels. Can a passenger engage with a handheld device while riding? Can a passenger be productive with their time?”
Researchers put 52 participants through a series of normal driving maneuvers at the Mcity Test Facility on U-M’s North Campus to develop the scripted route, instrumentation, and measurement protocol. The testbed consists of:
- A 20-minute test drive developed based on data from a separate real-world driving study. On average, it includes 25 braking events, 45 left turns and 30 right turns, and is conducted at both 10-15 mph and 20-25 mph.
- Tasks done on a handheld mini-iPad.
- Sensors that record vehicle acceleration and geospatial location and participant’s physiological response, including sweat, skin temperature, and heart rate. Cameras and sensors also record passenger head movement and posture.
- A new motion sickness rating using a 0-10 scale, with “0” indicating no motion sickness and “10” indicating “Need to stop the vehicle.”
- An open-ended conversation describing physical effects during the test drive.
With the protocol, researchers hope to develop a nuanced mathematical model of motion sickness—one that automakers can use to build products that operate below the threshold. Data from this testbed could inform decisions like how driverless cars brake and accelerate during turns, for example, or how the seating area and windows are arranged. Different control algorithms and car concepts can be tested and measured, apples-to-apples.
“We have found that passenger responses are complicated and have many dimensions,” Jones says. “Applications of this testbed will result in the data we need to identify preventative measures and alleviate motion sickness in autonomous vehicles.”