Sustainable mobility as a service: a scientometric review in the context of Agenda 2030

City planners are facing an emergency to develop, promote, and implement actions that allow the mobility needs of people and businesses in cities (and their surroundings) to be satisfied to assure a better quality of life. Among the different actions to promote, there is public transport, which should be the cornerstone of sustainable urban mobility. The only way to achieve the transition from private to public is by integrating services into a multimodal network and then encouraging interchange between different modes of transportation. In this context, the development of mobility as a service (MaaS) solutions is significant, and different studies have been developed in recent years. The paper thus introduces a scientometric review of such a topic in relation to the Sustainable Development Goals of Agenda 2030. The study focuses on the current state of MaaS implementation, trends, and research gaps, with an in-depth analysis of emerging themes, based on 819 documents selected from the WoS and Scopus databases. Introducing the database, and research methodology, an accurate interpretation of the data generated by the bibliometric analysis, and the primary evaluation parameters are outlined. The identified studies have been then categorized into three thematic groups with the intention of offering a comprehensive study that identifies the shortcomings and difficulties in the research carried out in these areas up to today. Particular attention is paid to how this research relates to the Sustainable Development Goals.