Scientific research in the field of road safety has been in progress at the British Road Research Laboratory for more than 20 years. For the past 10 years, studies have been made of the ways of protecting vehicle occupants. Detailed accident and injury investigations showed that the greatest need was to provide protection against injuries produced in frontal collisions. Data from American impact studies and from the Laboratory's own controlled impact tests provided the basic information on which protective measures should be based. Theoretical and experimental work showed that safety belts which also afford restraint to the upper part of the body were likely to be by far the most effective way of providing protection; this work is described.The development of standards and of testing methods is briefly discussed. An assessment of the value of safety belts in use in protecting car occupants in Great Britain is given.The paper also describes investigations into the protection value of padding material, safety glass, overall and detail design of vehicles, crash barriers and lamp standards.