TRANSITION is a UK wide Clean Air Network programme led by the University of Birmingham in collaboration with nine universities and over 20 cross-sector partners, which seeks to deliver air quality and health benefits associated with the UK transition to a low-emission transport economy. The academic investigators and policy, public, commercial and not-for-profit sector partners will undertake joint research, to co-define indoor and outdoor air quality challenges and co-deliver innovative, evidence-based solutions. The programme is funded through a £0.5 million UKRI (UK Research & Innovation) investment administered by the Natural Environment Research Council (NERC). The funding is part of the Clean Air Strategic Priorities Fund (SPF) Clean Air Programme which supports high quality multi- and interdisciplinary research and innovation linked effectively with government research priorities and opportunities. The Clean Air programme is jointly delivered by the Natural Environment Research Council (NERC) and the Met Office, with the Economic and Social Research Council (ESRC), Engineering and Physical Sciences Research Council (EPSRC), Innovate UK, Medical Research Council (MRC), National Physical Laboratory (NPL), Science & Technology Facilities Council (STFC), Department for Environment, Food and Rural Affairs (Defra), Department for Health and Social Care (DHSC), Department for Transport (DfT), Scottish Government and Welsh Government.