The timetable of a member of parliament is extremely full. It does not only include the work in the parliament itself. After all the plenary sessions and meetings of the parliamentary parties, and after dealing with their specific responsibilities and talking to representatives of various interest groups and institutions, a member of parliament's work continues in the constituency.
Here, he or she attends to the concerns of the citizens and meets up with local party members - usually in the evenings and weekends, when most people have finished their work. Without good time management, it would be impossible to fit in all these appointments.
The constitution grants members of parliament special rights (immunity and indemnity) so that they can exercise their mandates independently. They have a special right of free speech and can theoretically only be held accountable or arrested with the permission of parliament. They are basically also entitled to refuse to give evidence concerning persons who have confided facts to them in their capacity as members or to whom they have confided facts in this capacity.
The purpose of these rules is to ensure that parliament as a whole can work properly. However, the members of the State Parliament of Hesse have decided to impose restrictions on this immunity themselves and it is therefore possible to conduct proceedings against them in connection with criminal or disciplinary offences, such as provisional withdrawal of driving licences.