The individual EU member states are generally responsible for their own traffic and road safety legislation. This concerns speed limits, legal blood alcohol content, and the layout of roads, to give some examples. Only when measures clearly have a cross-border scope and EU involvement could have added value, does European legislation come into play. Vehicle safety, some road safety aspects of the Trans-European Transport Network (TEN-T), licence-to-drive requirements, and driving times and rest periods for commercial transport are, for example, governed by European legislation. European legislation always concerns minimum requirements. Individual member states or (the car) industry can apply stricter rules. An overview of European legislation can be found at ec.europa.eu/transport/road_safety/specialist/policy_en.
This sharing of responsibilities stems from the subsidiarity and proportionality principles the EU must comply with. The subsidiarity principle ensures that decisions are taken at the lowest possible level – i.e. in closest proximity to the citizens. A decision may therefore only be taken at the European level, if it cannot be taken at the national, provincial, or municipal level. The proportionality principle obliges the EU to choose the least intrusive means to intervene.
Apart from several types of binding legislation, the EU may also give non-binding recommendations and advice. A comprehensive description of several European laws can be found at ec.europa.eu/info/law/law-making-process/types-eu-law_nl#soorten-eu-wetgeving.