The need has been recognized for automotive occupant restraint systems that are capable of sensing specific occupant, vehicle and crash attributes in a given crash. The sensed values of these variables form the basis for modifying the performance of seat belts and airbags, and the interaction between them when both are involved, in effectively restraining an occupant in a crash. Systems with these capabilities have been dubbed "intelligent" or "smart" systems.

The current development and imminent application of "smart" systems has become possible because of the developments in seat belt, airbag and sensor technologies;​ the scientific and statistical information accumulated through the past several decades of research regarding human biomechanics and impact tolerance limits;​ the increasing availability of sensors with required capabilities at affordable costs;​ and the current levels of interest of governmental agencies, businesses and the public to obtain the social and economic benefits of "smart" systems.

Four basic areas of development leading ultimately to the installation in vehicles of "intelligent" restraint systems are (1) the characterization and implementation of sophisticated energy management in a crash event;​ (2) the development and application of suitable sensors;​ (3) the development and implementation of "smart" seat belt and airbag systems:​ and (4) the demonstration of the economic benefits to be realized through reduction of crash fatalities and serious injuries.