Passenger Seating Behavior and Discomfort in Middle Rear Seat: A Pilot Study

In this paper, a study was carried out about the perception of postural discomfort concerning the seating in the middle rear seat of a car. The aim was to identify which body parts are most stressed and which elements or factors involved in the human-car interaction cause major discomfort. Even if the literature confirms that postural-physical comfort is one of the crucial elements in car seat design, nothing has been made about the comfort and experience of the car's middle rear seat. A two-step analysis was conducted: a Preliminary survey and the Design of a valid experiment to investigate passengers’ discomfort perception in the middle rear seat. Twenty people participated in the test, two different car models (a City Car and a C-SUV) and a short ride were chosen to perform the experiments. Postural discomfort was assessed through questionnaires and using a 5-point Likert scale. Other factors were considered such as the interference of body parts with the vehicle’s tunnel and roof, and the presence of other passengers on either side of the middle passenger. Interference with other passengers and side thrusts when cornering affected the shoulders and arms discomfort. The headrests made the neck and head feel uncomfortable, while the central tunnel forced passengers to adopt uncomfortable postures for their lower limbs. The study highlights key elements that negatively impact passengers' perceived discomfort. The results obtained from this analysis can offer interesting suggestions for automotive manufacturers to improve passengers’ travel.