The 4th Railway Package is a set of 6 legislative texts designed to complete the single market for Rail services (Single European Railway Area). Its overarching goal is to revitalise the rail sector and make it more competitive vis-à-vis other modes of transport. It comprises two 'pillars' which have been negotiated largely in parallel:

The technical pillar addresses interoperability, safety authorisation, ERTMS track-side certification but also the reduction of national rules and the increased role of the EU Agency for Railways (ERA) to deliver authorisations and certifications.

The 'technical pillar' was adopted by the European Parliament and the Council in April 2016 and comprises:

The political pillar addresses market opening, tendering of public service contracts and access to national rail passenger markets.

The 'market pillar' was adopted in December 2016 and comprises: