(2)The rules on driving licences are essential elements of the common transport policy, contribute to improving road safety, and facilitate the free movement of persons taking up residence in a Member State other than the one issuing the licence. Given the importance of individual means of transport, possession of a driving licence duly recognised by a host Member State promotes free movement and freedom of establishment of persons. Despite the progress achieved with harmonising the rules on driving licences, significant differences have persisted between Member States in the rules on periodicity of licences renewal and on subcategories of vehicles, which needed to be harmonised more fully, in order to contribute to the implementation of Community policies.