The aim of the European funded Horizon 2020 project i-DREAMSis to develop, implement and evaluate a cluster of innovative real-time and post-trip interventions to improve road safety among both private and professional drivers operating different modes in road (i.e., car, bus, truck) and rail by means of a field trial with 600 participants in five different countries (i.e., Belgium, UK, Germany, Greece, and Portugal). This paper presents the theoretical paradigms of behavioural change adopted in the i-DREAMS interventions, and elaborates on the methodological framework used to determine intervention objectives, select suitable techniques for behavioural change, and further translate these into a series of gamification features to be integrated into an in-vehicle feedback display, and a smartphone app supported by an online web-platform.