This report was composed as part of Stronger Combined – an international R&I project funded by Interreg to explore the role of combined mobility, primarily within rural regions and areas. As such, this report examines the academic literature on Mobility-as-a-Service (MaaS) to investigate the geographical and conceptual areas that are covered by existing MaaS research and those which have been overlooked, aiming to deliver insights that can 1) spur developments in rural areas; and 2) inform future R&I programming within the broader MaaS field. Hence in addition to the above aims, this report also identifies gaps and shortcomings in academic scholarship, making recommendations for future research. The main findings of this report are summarized as follows: - MaaS is a concept forming in real-time. There is still much debate about the ‘true meaning’ of MaaS and the steps necessary to fully realize it. - MaaS research is overwhelmingly focused on urban places and populations. Rural and suburban areas are severely underrepresented in existing peer-reviewed research. MaaS for special populations and purposes like riders with disabilities or tourists is also underrepresented. - Authors of MaaS scholarship come from institutions in multiple countries, but 80% of articles come from seven countries: Sweden, Australia, UK, Netherlands, Switzerland, and Finland. These countries also tend to be the focus of MaaS research, although a sizeable number of articles are context-free (e.g. theoretical or conceptual). - Existing experimental and pilot-based research shows that access to MaaS has a measurable influence on individuals’ use of different travel modes, including a decline in personal vehicle use. However, multiple studies cast doubt on the ability of MaaS to displace personal vehicles completely. - The individuals most likely to adopt MaaS are mode agnostic – they already use multiple transportation modes for daily travel and are not strongly committed to any single mode. - Stated-preference surveys reveal that 10-15 percent of surveyed individuals are enthusiastic about adopting MaaS while another 30-40 percent are at least open-minded to the concept. The remainder are unlikely to adopt MaaS as currently conceived, for a variety of reasons. - Subscription-based MaaS with multiple bundled transportation services faces many obstacles including the complexity of service agreements and low stated-preferences for mobility bundles (albeit with exceptions). Several papers recommend that MaaS initiatives advance incrementally by including a small number of service providers and/or pay-as-you-go rather than subscription payment. - The governance of MaaS (i.e., the approach that different government entities take to making MaaS work) is critical. Different cities and public transit systems have approached MaaS governance in different ways. While there is no apparent “one-size-fits-all” approach, there is some consensus in the governance literature that enhanced data sharing, standardization, and participatory visioning processes have been and will continue to be important to the success of MaaS in the coming years. - The COVID-19 pandemic presents challenges to MaaS as conventionally envisioned, but some experts see opportunities for MaaS with expanded service offerings or as a tool for transportation resilience.