## 1 Introduction
\begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline
**Paper/Year** & **Ridesharing** & **Carpooling Carsharing** & **Bike Sharing Micromobility** & **Description** \\ \hline  & & & Reviewing bike sharing research based on 208 articles published between 2010 and 2018 and identifies several bike sharing topic categories such as factors, barrier, safety, health, behavior, impact, sharing economy and system optimization \\ \hline
[20]/2021 & o & Focusing on challenges and opportunities of rebalancing in dock-based bike-sharing systems based on articles published between 2010 and September 2020 \\ \hline
[21]/2020 & o & Reviewing the development, characteristics and impact of bike-sharing systems \\ \hline  & & A systematic analysis based on the articles related to bike-sharing and 642 papers published between 2010 and 2020 in the Web of Science (WoS) Core Collection was conducted and three categories of topics were identified, (1) operation mode, (2) static rebalancing problem and (3) demand prediction \\ \hline
[26]/2021 & o & Providing future research directions related to the role of micromobility in shaping sustainable cities by using a systematic literature review methodology based on 358 papers published between 2000 and 2020 \\ \hline
[27]/2021 & o & A review regarding use, health and environmental impacts, and policy implications of shared e-scooters based on 70 articles published between 2017 and October 2020 \\ \hline
[28]/2023 & o & Examining the key determinants, adoption and usage of electric micromobility from a public health perspective based on 67 articles published between 2010 and 2021 \\ \hline  & & A systematic review of the environmental impacts of shared electric micromobility services based on the lifecycle assessment method (20 studies were included in the analysis. They were published between 2019 and 2023) \\ \hline \end{tabular}
\end{table} 
Table 1: _Cont._access to multi-modal mobility transport services for users, the paradigm of Mobility as a Service (MaaS) has emerged. MaaS enables users to plan their itineraries, book the mobility services of different transport modes as needed and pay through a combined platform with multiple heterogeneous mobility modes. Although the vision of MaaS is to facilitate the provision of multi-modal transport services to users by simplifying the procedure to book the required transport services in a bundle based on user friendly GUI without having to book each required transport service one by one, it raises many unaddressed research issues to plan, design and implement MaaS for cities with multi-modal transport modes. These emerging multi-modal transport modes have not only received much attention from service providers and practitioners but have also attracted researchers' attention in related communities. These are reflected in the number of published review papers related to research issues of MaaS in cities such as [30; 31; 32; 33; 34; 35; 36; 37; 38; 39; 40; 41; 42; 43; 44], which are centered on Mobility as a Service only. A brief summary of these review papers related to MaaS are listed in Table 2.  
The factors that have been driving the strong growth of the number of published papers related to the emerging multi-modal transport in cities are the deficiencies of effective solution methods to accommodate the needs of users with multi-modal transport modes. Although the existing literature is still deficient in offering seamless end-to-end multi-modal mobility transport services, it provides valuable sources and clues for finding the life cycle of research subjects, issues and future directions. The goal of this study is to identify potential research directions based on analyzing the profile and trends of the recent multi-modal mobility transport literature obtained by searching the WOS database. The results of this study would pave the way for the assessment of research subjects, issues and directions related to MaaS, sustainability and shared mobility in the context of multi-modal mobility transport.