In an era of pressing environmental concerns, social equity considerations, and the urgent need for resilient urban infrastructure, the issue of sustainable transportation systems takes center stage. While standard definitions and theoretical frameworks for sustainable transport systems exist, there is a significant gap in our understanding of individual sustainable transport literacy (STL). STL is a pivotal factor in the development of environmentally responsible, cost-effective, and socially inclusive transport systems. Like other literacies, STL aims to elevate the level of communication and interaction, empowering individuals to understand the world and make informed choices that contribute to creating sustainable, liveable, and happy communities. This paper suggests the Sustainable Transport Literacy framework, a powerful tool designed to define and assess STL. This multidimensional eight-step framework includes key components and indicators that collectively measure a person’s understanding, skills, and commitment to sustainable transport. Based on the careful development of terminology, typology and system classification for STL concepts, as well as on the basis of overarching concepts of literacy, a definition of STL was proposed, and a preliminary assessment tool was developed. These efforts included creating a pilot test and questionnaire to assess knowledge and understanding of sustainable transportation principles, which underwent initial testing and content analysis.