This study aims to explore changes in uptake and cessation of walking, cycling and public transport use across the lifespan in a representative sample of UK adults aged 16 and older. A longitudinal analysis of 11,559 individuals in waves two (2010–2012) and six (2014–2016) of the General Population Sample (GPS) of the UK Household Longitudinal Survey (UKHLS) was performed. The outcome variables were self-reported and categorised as changes to and from 1) walking or cycling and 2) public transport. In adjusted models compared to younger adults (aged 16–34), middle-aged adults (aged 45–55: OR 0.66, p = 0.050) and older adults (aged >55: OR 0.53, p = 0.017) were significantly less likely to initiate walking/cycling during the study period. Middle and older aged adults were also significantly less likely to cease walking/cycling (aged 45–55: OR 0.68, p = 0.019; aged >55: OR 0.46, p < 0.001) and public transport use (aged 45–55: OR 0.33, p < 0.001; aged >55: OR 0.28, p < 0.001). Dose response relationships were observed where increasing age was associated with increased stability in transport mode. Developmental processes in early adulthood may contribute to self-selection and sustainability of active commuting in later life. Active travel programs and policies that target younger adults may be an efficient means to increase and sustain participation in active commuting.