The seat belt-shoulder harness restraint system is recognized as the most efficient, economical, available means of saving lives and reducing injuries in automobile accidents. A recent survey indicates that in accidents involving speeds up to 60 mph not a single motorist who was wearing seat belt-shoulder harnesses were killed. A recent report issued by a major auto-maker states that the seat belts-shoulder system is more effective from both a cost and life-saving point of view than the air bag or other presently proposed passive restraint systems.Despite the over-whelming evidenence and a concentrated public education program only about one-third of the American motoring public avails themselves of the protection of lap belts and less than 5% use shoulder harnesses. Recent government and industry tests indicate that this usage rate can be dramatically increased if all cars are equipped with a simple, inexpensive device that makes it impossible to start the car unless the seat belt and/or shoulder harnesses in all occupied seats are fastened. Among the testing personnel that either seldom or never previously used their belt system, 82% reported approval of this system and favored its installation in their next car. Recently the NHTSA approved the starter interlock system as an acceptable alternative to the passive restraint system until August 1975. This paper will briefly describe this system, the results of the government and other tests and delineate the dramatic increase in seat belt-shoulder harness use with the resultant reduction in deaths and injuries that can be achieved.