Technical Report UMTRI-2016-* June, 2016 Motion Sickness and Concerns for Self-Driving Vehicles: A Literature Review Paul Green Technical Report Documentation Page 1. Report No. 2. Government Accession No. 3. Recipient’s Catalog No. UMTRI-2016-* 4. Title and Subtitle 5. Report Date Motion Sickness and Concerns June 2016 for Self-Driving Vehicles: 6. Performing Organization Code A Literature Review account 355649 7. Author(s) 8. Performing Organization Report No. Paul Green project grant N021104 9. Performing Organization Name and Address 10. Work Unit no. (TRAIS) The University of Michigan Transportation Research Institute (UMTRI) 11. Contract or Grant No. 2901 Baxter Road, Ann Arbor, MI 48109-2150 USA ORSP 16-PAF0506 12. Sponsoring Agency Name and Address 13. Type of Report and Period Covered Yanfeng USA April 2016 – June, 2016 Advanced Product Development & Sales 14. Sponsoring Agency Code 701 Waverly Street, Holland, Michigan 49423 USA 15. Supplementary Notes Attention: Renae Pippel, Director - Strategic Research 16. Abstract Motion sickness is nausea induced by motion, especially when traveling in a vehicle. Motion sickness results from a mismatch of the visual and nonvisual (vestibular and kinesthetic) information, the observed scene and the motion felt or lack of it. Motion sickness is quantified using the Simulator Sickness Questionnaire (SSQ), the Misery Scale, the Well-Being scale, and other scales, and can be predicted using the equations in ISO 2641 and elsewhere. Commonly, motion sickness is assessed using some variation of the motion sickness susceptibility questionnaire. Children, women, and older adults are reportedly to be more likely to experience motion sickness. Current predictions of the frequency of motion sickness in self-driving cars are generally not based on actual driving, and where they are, the sample size is too small. Extrapolation from other transportation modes (airplane, buses, trains, etc.) is difficult because of differences in the motion experienced, trip duration, and other factors. How ride sharing will change the social dynamics of rider interaction and vehicle interior design is unknown. Should motion sickness prove to be an issue, design countermeasures include making sure the horizon is visible to all (reducing headrest blockage, not tinting of rear windows), stabilizing carry-in devices (smart phones, tablets, etc.), having everyone face forward, providing additional seat recline, and giving each person their own climate control, especially for airflow. 17. Key Words 18. Distribution Statement human factors, ergonomics, safety, No restrictions. This document is available driving, self-driving cars, automated to the public through the National Technical driving, motion sickness, simulator Information Service, Springfield, Virginia sickness 22161 19. Security Classify. (of this report) 20. Security Classify. (of this page) 21. No. of pages 22. Price (None) (None) 83 Form DOT F 1700 7 (8-72) Reproduction of completed page authorized i ii TABLE OF CONTENTS INTRODUCTION ............................................................................................................. 1 METHOD ......................................................................................................................... 3 WHAT IS MOTION SICKNESS? .................................................................................... 5 WHAT CAUSES MOTION SICKNESS? ......................................................................... 7 HOW IS MOTION SICKNESS QUANTIFIED? ............................................................... 9 HOW CAN MOTION SICKNESS SUSCEPTABILITY BE ASSESSED? ..................... 21 WHO IS MORE SUSCEPTIBLE TO MOTION SICKNESS? ......................................... 25 HOW LIKELY IS MOTION SICKNESS IN SELF-DRIVING CARS? ............................ 31 Ask People What They Think May Occur .............................................................. 31 What We Know from Self-Driving Car Studies ...................................................... 35 Extrapolating from Other Forms of Transportation .............................................. 37 Will Ridesharing Change the Rider Experience and the Tasks Riders Do? ....... 40 POTENTIAL DESIGN COUNTERMEASURES ............................................................ 43 Increase Field of View and Change Seating Position ........................................... 43 Stabilize the In-Vehicle Task ................................................................................... 47 MODELING MOTION SICKNESS ................................................................................ 51 How Much Debilitating Motion Has Someone Experienced?............................... 51 Example of a Contemporary Motion Sickness Model ........................................... 54 CONCLUSIONS ............................................................................................................ 56 REFERENCES .............................................................................................................. 65 APPENDIX A. VIRTUAL REALITY SYMPTOM QUESTIONNAIRE ............................. 71 APPENDIX B: MOTION SICKNESS SUSCEPTIBILITY QUESTIONNAIRE ................ 73 iii iv ACKNOWLEDGMENTS The author would like to than Reynerio Sanchez for his contributions to the editing of this report. 1 INTRODUCTION The report was funded by Yanfeng to assist them in the design and evaluation of future vehicle interiors for self-driving vehicles as well as to guide research to support that activity. Motion sickness is a potential concern because (1) the driver is no longer in control, (2) they may not face forward, and (3) they may engage in motion sickness inducing tasks, where motion sickness could increase, thus leading to decreased benefits of self-driving vehicles. The contract calls for addressing 3 specific issues as well as possibly others. Those core issues are: 1. What causes motion sickness? 2. What type of people are more susceptible to motion sickness? 3. What could be implemented or improved in vehicle interior design to alleviate motion sickness? As part of the process of reviewing the literature, it became apparent that the topics of quantifying the measurement of motion sickness, screening for susceptibility, and predicting motion sickness needed to be included to support moving forward, as well as quantitative models. Accordingly, this report addresses the following questions: 1. What is motion sickness? 2. What causes motion sickness? 3. How is motion sickness quantified? 4. How can motion sickness susceptibility be assessed? 5. Who is more susceptible to motion sickness? 6. How likely is motion sickness in cars? 7. What are some potential design countermeasures? 8. What are some quantitative models for predicting motion sickness? Quite frankly, at this point, the extent to which motion sickness will occur is a guess as what riders will do and the expected effectiveness of countermeasures to counteract motion sickness, should it occur, is unknown. 1 2 METHOD For the most part, Google Scholar was used to identify relevant literature. The first step was to identify overviews of the literature, searching using the terms “motion sickness” and “motion sickness review.” Those articles were read and key topics were identified. The second step involved searching for research that dealt with specific applications (e.g., “seasickness,” “car sickness,”), concerns (e.g., “motion sickness susceptibility,” “motion sickness individual differences”), standards (e.g., ISO 2641), models, and authors that have been major contributors (e.g., Robert Kennedy, Michael Griffin, Anthony Lawther, Ben Lawson, Jelte Bos). The third step involved taking the most highly cited papers and other papers of particular interest and seeing who cited them (and whom they cited). This provided for going both forward and backward in time to find relevant research. The final step involved skimming the numerous articles identified, sorting them into categories, and then carefully reading a subset of those in each category, and focusing on those pertaining to the questions identified. Given the schedule and resources available to this project, this review is not exhaustive. 3 4 WHAT IS MOTION SICKNESS? Motion sickness is nausea caused by motion, especially when traveling in a vehicle (https://www.google.com/#q=what+is+motion+sickness, retrieved May 20, 2016). Other symptoms include vomiting, headaches, sweating, increased salivation, drowsiness, dizziness, and warmth/flushing. Individuals with motion sickness also exhibit pallor (loss of skin color). Sometimes this term is more specifically identified (carsickness, seasickness, airsickness, space sickness, simulator sickness, or virtual reality sickness). Lawson (2015), reviewing the work of others, notes that a more technically correct term is motion maladaptation syndrome. Table 1, a modification of a table in Golding (2006), categorizes the situations in which motion sickness may occur. Table 1. Situations Which May Cause Motion Sickness Context Examples of Provocative Stimuli Land Cars, buses, trains, subways, skiing, camels, elephants, carnival rides Sea Ships, boats, ferries, survival rafts, diver’s lines undersea Air Small and large airplanes, helicopters, hovercraft, parabolic flight Space Shuttle, spacelab Optokinetic Wide-screen cinemas, centrifuge, microscopes, microfiche-readers, flight, driving and other simulators, virtual reality systems of all types, head-mounted displays, rotating visual