This report informs the UK Government’s Transport Decarbonisation Plan. It considers what needs to be achieved over the next 30 years, in terms of technological solutions, to reduce and remove direct emissions from the UK’s domestic transport sector across modes by 2050.In June 2019 the Government amended the Climate Change Act committing the UK to a net-zero contribution to global greenhouse gas emissions by 2050. Direct (tailpipe) emissions from domestic transport represent over a quarter of UK greenhouse gas emissions, making it the largest single source, 99% of which is comprised of CO2. In October 2019, the Government announced the development of the first Transport Decarbonisation Plan (TDP). To support the development of the TDP, the Department for Transport (DfT) asked Mott MacDonald and its partners, as part of the future resilience support they provide, to examine technological solutions for reducing and removing CO2 at point of use across all modes for domestic transport. In March 2020 the DfT published Decarbonising Transport: Setting the Challenge which confirmed the role of this study to “give advice on the support we need to provide in the near and medium term in order to de-risk, and have in place, the technologies which will help us deliver a decarbonised transport system by 2050”. The study’s purpose has not included consideration of the role of changing travel behaviour in reducing CO2 emissions from transport.This report sets out a series of seven roadmaps for decarbonising domestic transport in the UK. These roadmaps address: cars and light goods vehicles; buses; coaches; heavy goods vehicles; rail; domestic shipping; and domestic aviation. International aviation and shipping are not included within the scope of this study. These have been recognised by the Government as important to address through international co-operation and action, to which some of the solutions discussed in this report will contribute. It should be noted that in its Sixth Carbon Budget report published on 9 December 2020, the Committee on Climate Change (CCC) recommends that the legal limit for UK net emissions of greenhouse gases “should cover all greenhouse gas emissions, including those from international aviation and shipping”. The implications of this recommendation are not within scope of the roadmaps in this report.Each roadmap considers the progression of relevant candidate technology solutions. The roadmaps work backwards from an achievable 2050 end state aligned to the goal of decarbonisation, identifying developments and milestones over the period between 2050 and 2020 that would enable the 2050 end state to be reached. Developments are centred – especially for road transport - upon fleet turnover (the replacement of CO2-emitting vehicles with zero-emission vehicles) and the supporting infrastructure (for refuelling/recharging those zero-emission vehicles). Underpinning the developments, the roadmaps set out recommended research and innovation interventions that need to be progressed in the coming five to ten years. The roadmaps also consider the recommended role of policymaking and fiscal/regulatory measures in helping to enable progress