The opening up to competition of passenger rail transport is one of the key issues in Europe, both in view of the completion of a common European railway market and regarding the objectives of sustainable mobility and a climate neutral economy by midcentury defined within the European 2019 Green Deal.The railways market was one of the last infrastructure-based sectors to be covered by EU law. It is true that since its creation in the 19th century, rail transport has always been an issue for governments, as a symbol of public service. It was only in 1991 that the EU initiated the transformation of the sector and its opening up to competition with the first Railway Package. The fourth railway Package, adopted in 2016 has fully completed this liberalization process for national passenger transport.Seven years after its adoption, the EU regulatory framework for the railways sector has now reached maturity. It is therefore a perfect moment for an evaluation of the process, as competition in passenger services is emerging, including in the late comer members states.How effective actually is this opening up to competition in Europe? In order to get a precise view of the diversity of situations in Europe, this book focuses on the legal framework of the railway sector in the most relevant European States (Germany, Austria, Spain, France and Italy) and on how the competition has been introduced. It then reviews the litigations arising from the opening up to competition at both the national and European level.This publication is the outcome of a conference organised at the Paris Dauphine-PSL University on 3rd February 2023, directed by Professor Aurore Laget-Annamayer and bringing together academics as well as public and private actors. It is aimed for all those interested in the evolution of the railways sector, including students, academics and professionals. By exposing the strengths and weaknesses of its opening up to competition, it should contribute to a better understanding of a sector whose role has become essential in view of the ecological transition.