The sample (n=100) is derived from the experienced (n=1003) and novice drivers (n=1866) databases of Estonian Psychobiological Traffic Behaviour Study (EPTBS). For testing the reliability and validity of the tests, at first a series of tasks will be carried out in a pilot sample (n=30). The final testing battery will be selected and carried out in a bigger sample that is selected from the existing database according to the specific traffic risk factors. Earlier measures include the impulsivity and attention deficit scale scores, self-estimated skills, and objective data on traffic behaviour like accident and violation records, and response to a brief psychological intervention in driving school. On one hand, uniting the results of the planned cognitive tasks with the data from the earlier database enables to validate the mentioned tests. On the other hand, testing cognitive abilities in risky drivers helps to understand the specific mechanisms behind their risk-taking. Finally, the acquired data enables to test hypotheses on the cognitive nature of impulse control – for example, whether the underlying reasons for apparently impulsive behaviour are in the preference for speed over accuracy, problems in inhibition process, subjective tempo or acknowledged risk-taking.