Current car seat design is based on safety, comfort and functionality. It has been recognised from previous research projects that people of short stature may find it difficult to reach primary controls in a vehicle or obtain an adequate view for driving. Even with current seat adjustments some drivers require a seat for height or comfort, a cushion that either lifts them up in the seat or forward in the seat. Disabled drivers are also known to use cushions to improve comfort whilst driving, such as pressure reduction cushions to reduce the risk of sores. Previous research has highlighted that there is likely to be an increased risk of injury to the driver during a crash whilst using these devices. As a result, the Department for Transport’s Mobility and Inclusion Unit has commissioned research to investigate this theory further. This project investigates the likely increase in risk of driver injury, caused by the inclusion of additional cushions in vehicle seats. The main aims of this project are to: • Provide an assessment of the risk of injury through using a seat cushion in the event of an Impact. • Provide recommendations for drivers using these devices to enable them to minimise their risk of injury. • Provide guidelines that assessment centres can use when advising drivers who need an auxiliary support device. The study has shown that there is a wide range of cushions available in the market today and that the cushions are used for a range of purposes. It was therefore important to ensure that the evaluation looked at a range of cushions and a range of users e.g. drivers with physical disabilities, drivers of short stature etc. The literature review that was undertaken during the study has shown that there are many passive safety features included as standard on vehicles today. The introduction of a cushion into the vehicle may effect the performance of the various safety systems, such that in an accident the system may no longer give adequate protection to the driver. In order to investigate the effect of the use of cushions a programme of impact testing and mathematical modelling was conducted, looking at the performance of a range of cushions, in a number of impact scenarios. The results suggest that it is not possible to make a generalised statement as to whether the use of cushions will or will not have a detrimental effect on occupant injuries in a vehicle impact. Different cushions effect performance in different ways, depending on the direction of impact and the size of occupant. Therefore in order to assess the suitability of the use of a particular cushion, each situation must be assessed separately and the following questions should be asked: • What safety systems feature on the vehicle? • Will the cushion interfere with the operation of the safety systems? • How does the cushion effect the seating position of the occupant? Attempts should be made to ensure that the cushion does not interfere with the operation of the existing safety systems and that it does not place the occupant too far forward or too high up in the seat. The user should be made aware that addition of the cushion may effect the performance of the existing restraint system in the event of an accident. (Author/publisher)
Samenvatting