The study consists of four separate experiments conducted in the VTI driving simulator. The common theme was to investigate how driver behaviour and traffic safety are influenced when the driver attends to another technical device while driving. The experiments were concerned with handsfree or handheld mobile phone conversation and dialling, receiving mobile phone SMS messages and watching a DVD film (the latter two being minor pilot experiments). 

In three of the experiments (mobile phone conversation, SMS, DVD) the participants drove a route which led through urban and rural environments, ranging from 90 km/h rural to 50 km/h urban environments. The urban environments differed in complexity (three levels). The driving distance was about 70 km. The dialling experiment used a rural environment with a speed limit of 110 km/h. The driving distance was about 15 km. In the main experiment dealing with mobile phone conversation, a number of driving performance measures were analysed: driving speed, variation in lateral position, deceleration, brake reaction time, headway, time to collision, etc. PDT (Peripheral Detection Task) was used as a measure of mental workload.