The purpose of this chapter is to present the reader with an overview of what behaviour means in the context of travel by providing an overview of the relevant academic developments that aim to unpack travel behaviour; highlight notable theoretical and conceptual frameworks; illustrate key points with relevant case studies; and discuss the implications of these findings for behavioural change research. In order to do so, the chapter is structured as follows. The first section provides an overview of the relevant developments that have aimed to unpack travel behaviour, giving consideration to the traditional approaches and how they have evolved. The second section highlights the relevant theoretical and conceptual frameworks of travel behaviour, noting the advantages, disadvantages and drivers to behaviour change from each framework and how they compare to one another. The third section provides relevant case studies that illustrate the points made in the previous sections. The final section discusses the implications of these findings for behavioural change research, drawing from recent works in behavioural economics and habit research.