Drivers are issued with a tachograph smart card, so called ‘Driver Card’. The card constitutes the personal file of that driver. On it, all drivers’ activities are stored and the card contains at least 28 days of activities in which the latest data overwrites the oldest one. It is important to insert the card in the equipment right at the start of a working day. Only then is the working time recorded from the beginning. However the card must be at disposal all times, even when a vehicle is equipped with a mechanical tachograph.