The Traffic Accident Research Unit was charged with commissioning, monitoring and assessing the effects of the publicity campaign, and with conducting the investigation of motorcycle electrical systems. In addition, the opportunity was taken during the period of the campaign to undertake a questionnaire survey of motorcyclists, seeking attitudes towards daytime headlamp use. There were thus three major components of the investigation: (1) an assessment, by means of roadside observational surveys, of the extent to which the publicity campaign influenced the daytime use of motorcycle headlamps; (2) an appreciation, by means of a questionnaire survey, of motorcyclist attitudes and opinions concerning the daytime use of motorcycle headlamps; (3) an examination, by means of laboratory and field tests, of the ability of motorcycle electrical systems to withstand daytime headlamp use.