Evaluating an Intervention to Improve Belt Fit for Drivers

Abstract

Previous studies have demonstrated that many drivers position their belts suboptimally. The lap portion of the belt is often higher and farther forward relative to the pelvis than would be ideal, and the shoulder portion of the belt is often placed more outboard than the position that would provide the best restraint. This project evaluated the performance of a video-based intervention and a subsequent scripted in-person interaction for improving the belt routing obtained by drivers. The belt fit video intervention can be found here: doi:10.7302/Z23B5X3K. Twenty-nine adult drivers participated in this study. Belt fit was measured before and after the intervention in participants’ vehicles and in a laboratory mockup. Standard anthropometric measures were obtained and the participants completed several questionnaires to document participant health beliefs and to assess how the participants perceived the video intervention. The results provide preliminary evidence that an intervention could improve driver belt fit. Data from both the invehicle and in-laboratory belt measures found that 93% of participants sampled improved some aspect of lap belt fit in response to the intervention. Participants who lowered the lap belt location (Z) after the intervention, showed an improvement of 40 mm on average. This delta value is slightly less than the width of the belt used in this study (45 mm). Among those participants who shifted the horizontal lap belt location (X) rearward, closer to the pelvis, an average improvement of 50 mm delta was observed. Indices of behavioral modifications also aligned with the belt fit score improvements. More research will be needed to establish whether this intervention would be effective outside of the laboratory setting.