Proximity to the steering wheel for obese drivers

Obesity increases the risks to motor vehicle occupants of some types of injury in crashes. The effects of obesity on injury causation are not well understood and current prevention efforts do not effectively address the increased vulnerability of individuals with high body mass index (BMI). Proximity to the steering wheel has been associated with increased risk due to airbag deployment, and the steering wheel rim is a source of injury in frontal crashes even with airbags. This study examined the spatial relationship between the steering wheel and drivers with high BMI in a midsize sedan package condition. Driving postures of 52 men and women with BMI from 31 to 59 kg/m (median 38 kg/m) were measured in laboratory mockup configured to be representative of a midsize passenger car. Three-dimensional body shape data captured using a laser scanner were aligned to landmarks measured in the driving posture to quantify the relationship between the torso and the steering wheel. Consistent with previous research, higher BMI was associated with decreased clearance relative to the steering wheel. Many drivers with high BMI can be expected to sit with their torsos within 100 mm of the wheel rim. The results suggest that attention should be paid to airbag deployment kinematics and efforts to mitigate the potential for abdominal injury due to steering wheel rim loading for these drivers. A continued focus on improving vehicle and restraint system design for individuals with high BMI is needed.