Elderly occupants form a sub-group in the population spectrum that is often categorized as “vulnerable” in the automotive industry. By 2050, the segment of the population aged 60+ is expected to approximate 26%, which reinforces the importance of developing more adaptable safety technologies that provide optimal and accessible restraint. Following previous research where we analyzed the performance of motorized adjustable buckles in increasing the ease of access to recessed belt buckles for children in booster seats, we extended the examination to study their applicability to elderly occupant comfort and safety.

Thereby, the objectives were:​

1. Perform a series of usability studies to prove that the current industry trend of recessed buckles is causing accessibility issues.
2. Attempt to confirm if motorized adjustable buckles improve latching performance while maintaining the intended geometry, given the previous objective was proven true.

A series of studies were conducted with a fixture that simulated the rear right side seat of a mid-sized sedan. The fixture was equipped with a motorized adjustable buckle which replicated two buckle modes – recessed and elevated. Occupants were asked to latch themselves with the buckle in both positions. Observations were made of the number of latch attempts, latching times, occupant preferences, and difficulty levels. The data shows a statistically significant difference for the mean latching attempts and durations between the two buckle modes (recessed and elevated). Objective feedback collected from the occupants shows that a majority of the sample population preferred the elevated mode. However, a strong explanation by the predictor variables (age, sex, weight, standing height, sitting height, arm length, arm to buckle length, and location) of response variables (latch attempts and durations, and buckle preferences) could not be established, unlike our previous study where strong correlations were found. This study’s results indicate that elderly occupants are influenced by categorically different factors than children, as variables like age, weight, height, and sex had a limited influence on the outcome of the study. Observations and analyses conducted during the trials point towards more subjective factors that may have had a greater impact on the outcomes;​ predominantly general health, which can be arbitrary and indifferent to the predictors that were considered in this study. Furthermore, a singular seating configuration was used in this study. More permutations of seat sizes and buckle mounting types will aid in confirming this study’s hypotheses.