Abstract
This paper describes the Swedish national research project DROWSI. The DROWSI project aims to perform basic research to better understand drowsy driving and to develop effective countermeasures using a multi-disciplinary approach. Several unique experiments with sleep deprived drivers have beenperformed both in high definition simulator and on public road in instrumented cars and trucks. In addition, legal issues and cost and safety benefits have been investigated. The combined experience from these studies hasbeen used to design a driver support system and to propose method for deploying these in day-to-day operations of a truck fleet operator.