This study explores consumers' behaviour regarding sustainable mobility options. A mixed‐methods approach was adopted to examine the impact of bio‐altruistic values, egoistic values, environmental attitudes, attitudes regarding sustainable mobility, perceived behavioural control and subjective norms on the likelihood of choosing sustainable mobility options. To collect the data, an online survey was applied to a sample of 645 Portuguese consumers, which included one single non‐mandatory open‐ended question to understand which factors could contribute to increase respondents' likelihood to choose more sustainable transport modes. As most studies in the mobility field are quantitative, combining both quantitative and qualitative data provided a greater in‐depth analysis with richer findings. Firstly, findings revealed that attitudes towards sustainable mobility, subjective norms, perceived behaviour control, and egoistic values influence the likelihood of choosing sustainable mobility options. However, environmental attitudes, altruistic and biospheric values do not impact this choice. Secondly, consumers highlight that the existence of a broad public transport network, safe bicycle lanes, and accessible prices would contribute to their likelihood of adopting more sustainable mobility behaviours. The content analysis of 402 answers allowed to discover new dimensions that influence sustainable mobility behaviour, such as safety, respect towards bicycle users, mindset adjustment, willpower, and especially physical efforts associated with long distances, bad weather, orography, and the difficulty to transport materials or other people. Based on both quantitative and qualitative findings, the paper provides key recommendations for politicians, urban planners, and transport organisations, that according to respondents, would contribute to increase their use of sustainable mobility.