Differences between obese and non-obese drivers in preferred vehicle interior components setting and driving posture.

This study compared obese and non-obese drivers in the preferred seat and steering wheel setting and preferred driving posture. Twenty-one extremely obese and 23 non-obese drivers participated. Each participant determined the most preferred setting of the interior components using an adjustable vehicle mock-up; the preferred components setting and corresponding preferred driving posture were recorded. The participant groups exhibited significant differences in the preferred interior components setting. The obese group created larger steering wheel-seat space than the non-obese, with greater rearward seat displacement, more upright steering wheel angle and smaller steering wheel column displacement. It also exhibited more upright seatback angle deemed necessary for facilitating steering wheel reach with the increased steering wheel-seat distance. The between-group differences in the preferred driving posture were less pronounced: no significant group mean angle differences were found except for the elbow joint angles. Also, the mean hip joint centre positions did not significantly differ. Practitioner Summary: To contribute to larger driver packaging, this study compared obese and non-obese drivers in the preferred vehicle interior components setting and driving posture. The obese group created significantly larger space between the steering wheel and seat than the non-obese, through interior components adjustments. The between-group postural differences were less pronounced.