The growth in tourism has brought benefits but also pressured urban transportation systems, particularly in capitals where it intersects with business and local life. While urban sustainable mobility development typically centers on the transportation needs of the residents, it frequently neglects the unsustainable travel habits of tourists. This study focuses on the key elements influencing sustainable tourist transportation, stressing the imperative for city administrations to tackle this concern. Based on a study of ten European capital cities and 5220 individual tourists, unique perspectives on urban tourist transportation are provided. Initially, a DCSM index (Destination City’ Sustainable Mobility Index) was crafted to mirror the sustainability of urban transportation systems, integrating data on cities’ transportation modes and factors promoting sustainable transportation while deterring unsustainable options. This index was then embedded in an ordered logit model, with the sustainable transportation choices of tourists as the dependent variable. The findings show that the traits of the destination city and the transportation preferences from the tourist’s home location, combined with accommodation and trip details, considerably influence their transportation decisions at the destination. These insights underline the potential to mold sustainable tourist behaviors by advancing environmentally friendly transportation systems, enhancing urban planning, and optimally positioning hotels. However, it is vital to acknowledge that without influencing tourists’ routine behaviors at home through education, their travel choices might persist. This research underscores the need for holistic strategies that integrate both destination-specific actions and pre-trip educational initiatives to truly promote tourists’ sustainable transportation behavior.