Literature Review: Why do we need innovative design methods for future Mobility-as-a-Service (MaaS)?

•Maas has undergone three developmental stages over the past decade, currently prioritizing a user-centric approach to enhance understanding of the user value proposition.•Future iterations of MaaS are influenced by users’ lifestyle aspirations, shaping the architecture and touchpoints of service systems.•Innovation in the MaaS ecosystem is expanding beyond transport services to include non-transport services, significantly broadening its scope.•Design perspectives will play a critical role in addressing challenges such as value proposition mismatches, risks of market monopoly, and issues related to social equity.•Design co-creation serves as a crucial link connecting service design logics, facilitating the achievement of long-term sustainability objectives. Since its inception in 2014, Mobility-as-a-Service (MaaS) has been the subject of numerous trials and pilot studies globally, predominantly yielding favourable outcomes. However, specific issues that need to be clarified regarding its long-term development have been observed. This paper outlines the development stages of MaaS and the trials conducted across different nations. It highlights an ambiguity within user-centred design in the extant literature, specifically the inadequate exploration of user requirements. The discourse propounds the necessity for a paradigm shift in the research focus—advocating for a more profound inquiry into user needs instead of the prevailing emphasis on the advancement of enabling technologies and the operations of digital platforms. Given the increasing demand for personalisation within intricate transportation systems, comprehending users’ cognitive and psychological preferences emerges as paramount. Such an understanding is imperative to allow the service framework to adapt and identify principal offerings that resonate with user inclinations. Moreover, establishing an enduring dialogue between service providers and users is essential. The paper argues for design researchers to formulate and implement an innovative methodology that fosters the alignment of supply with demand, thereby enhancing the efficacy of Mobility as a Service.