Studies show that Mobility-as-a-Service (MaaS) could decrease the use and ownership of private vehicles and support a switch to active travel modes and transit [1], [2], [3]. However, the magnitude of this switch is not comprehensively explored among the literature [2]. According to one simulation study, MaaS could reduce emissions by up to 54 percent, depending on the modeling scenarios [4]. Another simulation study showed that MaaS could reduce transport-related energy consumption because of the introduction of car-sharing and bike-sharing services [5]. Another study suggested that MaaS could reduce vehicle miles traveled and related negative externalities [6].

Several research directions are promising for future studies. First, there are limited studies on what drives people to use MaaS, highlighting a need to explore user incentives to adoption. Understanding these factors can inform more targeted service design and marketing strategies. Second, modeling the integration of multi-modal travel within MaaS is crucial. This could offer insights into optimizing traffic flows and enhancing the environmental and social benefits of MaaS. Third, the collaborative mechanism between the public and private sectors in the MaaS ecosystem requires further examination. Investigating how these entities can better cooperate could foster the broader application of MaaS solutions.