Current leisure mobility patterns are not sustainable. Because energy efficiency measures appear insufficient to accommodate predicted future volume growth, changes in transportation modes and volume are needed. Short-haul should be the preferred distance, public transportation the preferred mode and length of stay should increase rather than trip frequency. However, tourists are unwilling to adopt these changes. This paper proposes a new conceptual "three-gear model" demonstrating how happiness, travel motivations and perception of distance set barriers for desirable behavioral change. The model improves understanding of the gap between awareness of, and attitudes to, tourism mobility and the gap between environmentally friendly everyday behaviors and unsustainable vacation behaviors. The paper shows that happiness is integral to all stages of the tourist experience. Understanding happiness enhances the understanding of tourist behavior, and how it drives, via the speed-distance-demand loop, the three-stage model presented here. Key practical implications include the need for effective policies to break the speed-distance-demand loop, changes to transport infrastructure policies, and recognition of the role of happiness in sustainable tourism strategies. Theoretical contributions include a synthesis of theories to interrogate key behavioral gaps and a theoretical basis for future empirical studies.