The FIA Foundation Research Paper series explores the future of road transport emissions regulation in the UK after Brexit. The paper, written by Tim Williamson and Richard German of Aether, a UK-based environmental consultancy, provides insights into current issues and uses rigorous data analysis to generate conclusions relevant to global and local policy debates. The authors of the paper focus on the potential impact of Brexit on UK road transport emissions regulation, including the potential for increased regulation and the need for the UK to develop its own emissions standards. The paper also highlights the importance of collaboration between the UK and other countries to address global emissions challenges. Overall, the paper provides a comprehensive overview of the future of road transport emissions regulation in the UK after Brexit.