Expanding and improving road network in India has been a catalyst for increased use of road transport in both passenger and goods sector. With improved road quality, bigger commercials vehicles have entered the market. These provide a larger cabin area and better amenities in the truck driver cabin. One of the most welcome features is berths for lying down and sleeping. In most designs though, only the functionality of the berth has been taken into consideration. Safety of the occupants of the berths in the event of panic braking or collision of the vehicle, has not been given adequate consideration.
In this work, design of such berths from occupant safety point of view has been assessed. Kinematics of occupants, sleeping in different typical postures, during frontal impact, has been simulated and resulting critical injury levels have been estimated.
Based on this information, different arrangements of belts in “screen” type configuration were developed. The aim of this design was to restrict movement of the occupants within the confines of the berth, preventing the possibility of them coming off the berth and hitting other parts of the cabin interior. Effectiveness of the restraint systems was assessed based on injury levels for head, thorax, pelvis and chest of occupants. It was found that use of these restraint systems has the potential to reduce HIC levels of the occupants by 25% (for Fetus 1 sleeping position) to 60% (for Soldier sleeping position). Similar reductions were obtained for other injuries also.