## 3 Review of Studies Related to MaaS in the Context of Multi-
### Review of Studies
Results: In [47], the authors attempted to answer the question \"Does MaaS address the challenges of multi-modal mothers?\". The authors identified the needs of mothers from their perspectives to answer this question. By analyzing MaaS and comparing MaaS with the existing system from the perspectives of transportation, technology, policy, subject and economics, the study found that the needs of participants include conveniently accessible stations, tram with strollers and infrastructure. The authors suggested that offering different micromobility vehicles such as shared cargo bikes or electric bikes and the functions to plan and make an advance reservation can be beneficial for mothers. 3. Question: How to develop a general modelling framework for MaaS based on analysis of the relevant literature considering main actors and factors? Results: Due to the lack of a model to fully represent the diverse travel needs of users' and aspects of the interaction between choices, a generic framework need to be proposed to model MaaS. In the paper [65], a generic framework considering the factors of (i) socio-economic characteristics, (ii) attitudes and habits of the travelers, and (iii) MaaS-related factors has been proposed to model MaaS to capture users' diversified needs and the service providers' conflicting objectives. 4. Questions: What are the requirements of MaaS? How to develop a sustainable business model for transport operators at varying levels of MaaS considering risk and data sharing? Results: There lacked a study on the requirements of a sustainable business model for transport operators at different levels of MaaS considering risk and data sharing. The authors of [97] proposed a MaaS Lite model to focus on the users and the end-to-end trips. The MaaS Lite model aims to deliver a user-centric multi-modal mobility services and overcome many barriers to implement MaaS such as institutional inertia, poor scalability and lack of trust. 5. Questions: Who and why users took part in the trial of a MaaS service? Whether the trial experience satisfied the users' motives? Results: To understand who and why users took part in the trial of a MaaS service in Sydney and whether the trial experience satisfied their motives, analysis based on questionnaires and interviews was performed in [48]. The study of [48] indicates the conjecture that MaaS does not appeal to private car users is not correct, which implies that multi-modal travelers are potential trend setters of MaaS. The study found that the main motive to take part in the trial is a wish to contribute to innovative MaaS services and curiosity about the new multi-modal transport. 6. Question: How MaaS could impact GHG emissions in an urban setting? Results: The question about the impact of MaaS on GHG emissions is of interest to the government transportation planners as it is responsible for introducing and promoting sustainable transport. In [84], the authors studied how MaaS could impact GHG emissions in an urban setting. Three scenarios of how MaaS could impact GHG emissions in an urban setting were studied based on activity-based model for Amsterdam, the Netherlands. The study indicated that the implementation of MaaS might lead to emission reductions. The attractiveness of MaaS will largely determine the emission reduction potential. 7. Question: How to simulate multi-modal operations of Mobility as a Service in low-density cities? Results: Due to the shortcomings of traditional transportation planning without considering the aspects of adoption, partnerships, capacity, operations, integration, and impact on multi-modal planning of low-density cities, simulation of multi-modaloperations is required. A simulated MaaS network was used in the study [66] to evaluate a variety of metrics and inter-modal interactions based on experiments in International Drive in Orlando, Florida.