This study was the first of a series looking at the development of model work-rest schedules that have demonstrated effectiveness in managing driver fatigue. The aim was to develop a range of performance tests with demonstrated sensitivity for fatigue and for which the fatigue effects could be interpreted on the basis of a community-accepted standard for safety. Performance effects were studied in the same subjects over a period of 28 hours of sleep deprivation and following measured doses of alcohol up to approximately 0.1% Blood Alcohol Concentration (BAC).