This paper compares various concepts in occupant restraint protection such as inflating restraint systems and various belt arrangements. The source of information is a large body of impact sled test data which has been gathered at the Highway Safety Research Institute within the past year. It will be demonstrated that the level of effectiveness possible with an inflating restraint system is significantly greater than that with various belt systems based on the level of protection offered and on the rate of usage. The index of protection or injury criterion which has been used in this work will be discussed and compared with other recent developments in the area of human tolerance.