The UK Government restrictions on non-essential work in response to the COVID-19 pandemic has meant that millions of working aged-adults were forced into an unplanned lifestyle change. We present data on changes in commuting behaviour of public transport and car commuters and describe the facilitators and barriers to switching commuting behaviours, with a specific focus on cycling and walking.An online survey queried individuals’ transport mode to/from work before becoming aware of COVID-19 threat, when restrictions were in place and the transport mode they may use once restrictions are lifted. Free-form text responses were also collected on why they may switch to a sustainable mode of transport (e.g. walk, bicycle or bus) to work in the future and what would help/allow them to achieve this. Quantitative and qualitative data on those who commuted by car (single occupant) and public transport (bus/rail/park & ride) were analysed and presented separately.Overall, 725 car and public transport commuters responded; 72.4% were car commuters and 27.6% were public transport commuters before COVID-19. Of the car commuters, 81.9% may continue travelling by car once restrictions are lifted while 3.6% and 6.5% might change to walking and cycling, respectively. Of the public transport commuters, 49.0% plan to switch modes. From the free-form text responses three themes were identified: (a) perceived behavioural control towards cycling and walking (infrastructure and safety of roads, distance, weather) (b) key motivators to encourage a switch to cycling and walking (provision to support cycling, personal and environmental benefits); (c) the demands of current lifestyle (job requirements, family and lifestyle commitments).These UK data show how the COVID-19 pandemic has been an “external shock” causing some individuals to reassess their commuting mode. This provides an opportunity for theory-based behaviour change interventions tackling motivations, barriers and beliefs towards changing commute mode.