Drowsiness and lack of alertness while driving are major causes of traffic accidents. An attention support system that detects periods of inattention would greatly improve safety on the roads. This thesis for a Master of Sci- ence degree presents a pilot study from the Driver Drowsiness and Vigi- lance project at Volvo Car Corporation. Using Real-Life driving a statistical analysis has been performed based on data from physiological reactions, driver operations and vehicle conditions. The analysis focuses mainly on eyelid movements. A Volvo S60, with an attention support system installed, was available to collect data. Six people participated in the test sessions. Driver response was recorded during both short and long duration drives. Analysis was done of differences between drivers regarding their normal driving behaviour and changes in driving behaviour over time. The analyses showed large individ- ual differences and signs of driving impairment due to long driving duration and drowsiness. At the same time an evaluation of the attention support system was carried out which shows a system that has good potential to help drivers to detect drowsiness and inattention, but it must improve greatly before it can be launched on the market.