This new Thematic Research Summary (TRS) aims to provide the reader with a synthesis of results of completed European research projects related to regulation and deregulation. Regulation, in the context of this theme, is defined as the use of physical regulation or the law to correct what is perceived to be failure, particularly market failure, in the transport sector. Regulation may also be used to achieve specific transport objectives, such as safety. Deregulation is the removal of regulations, often in order to adjust competition policy.This new TRS helps the reader keep abreast of the latest research in the EU on the topic. The first part includes a brief overview of the scope of the theme and summarises the main policy developments at EU level relevant to the theme. The second part contains a synthesis of the main findings and policy implications from research projects and identifies the implications for further research. The new TRS is available for download from the Thematic publications section of the TRKC website.