Buses are one of the safest modes of transport available and one of the options that governments in Europe are especially trying to promote, in order to meet congestion and emission targets. When a bus accident occurs it often becomes the focus of media and public attention, especially because the people involved had confidence in the transport and sometimes it is their sole transport reliance. In particular, school bus accidents cause great public anxiety and often make the relative safety of buses be overlooked. While the incidence of bus occupant trauma is relatively low, there is concern on how best to improve bus safety.

Three-point seat belts are a good way of improving the level of protection for occupants and it is likely that future legislation worldwide will move towards compulsory installation and use in buses. One of the problems with conventional three-point seat belts is that they need to be compatible with child restraint systems to be effective for children;​ otherwise the shoulder belt adds a significant risk of injury. There is an availability problem of sufficient numbers of universal child restraint systems for different mass categories (G0/G0+, G1, G2 and G3 according to ECE R-44) that ensure an adequate level of protection for occupants of all age groups. If child restraint systems are vehicle specific or integrated there is still a problem with adjustments and there is evident risk of misuse.

This paper describes the development of a new concept of three-point seat belt for buses that is compatible with adults and children over 3 years, and self-adjustable. Applus+IDIADA designed, developed, tested and patented the system under contract to FITSA (Spanish Foundation Institute of Technological and Automotive Safety). This concept intends to provide an effective, inexpensive solution to the safety of children in buses.