## 4 Review of Studies Related to Sustainability in the Context of Multi-Modal Mobility
### Review of Studies
This study also finds that improving the public transport service with micromobility network, increasing parking costs and limiting parking capacity are helpful for reducing vehicle use and making mobility more sustainable. 10 Question: How to develop a framework for modeling traveler behaviors and incentivize travelers to select more sustainable travel options in on-demand mobility services? Results: A framework for accounting the impacts of real-time on-demand mobility on traveler behaviors and modeling heterogeneous characteristics of consumers for integration with multi-modal dynamic simulators is essential for understanding traveler behaviors in response to on-demand mobility services. In [71], a framework considering sequential and inter-connected decision-making stages of on-demand service usage was proposed. The framework consists of a hybrid service subscription choice model, and logit mixture models for service access, menu product choice and opt-out choice. The framework was applied to a case to incentivize and encourage travelers to select sustainable travel options. The incentives and schedule delay perception were quantified by different population segments. 11 Questions: Is there a connection between transport mode choice and travel satisfaction? Is it possible to identify the connection between transport mode choice and travel satisfaction? Results: Understanding the connection between travel satisfaction and mode choice is an essential research issue as it provides important insights into formulation of transport policies and prioritizing resources to achieve sustainable mobility patterns. The paper [55] focused on the study of the connection between mode choice and travel satisfaction by incorporating the model of human needs and travel satisfaction in the framework. The findings of this study include: (1) Car use satisfaction is positively related to transit use difficulties, and is negatively related to functional difficulties in car use and better cycling self-efficacy. (2) Bicycle satisfaction is related positively to cycling self-concepts and self-efficacy and is related negatively to car self-concepts. (3) Transit satisfaction is positively related to experiencing difficulties with other modes. 12 Questions: What are the factors that drive the adoption of ride-hailing and the associated travel characteristics? Are there mode substitution effects for ride-hailing? Results: Studying the factors that drive the ride-hailing adoption and the associated travel characteristics is important for providing mobility-on-demand services. The paper [56] studies the factors that drive the ride-hailing adoption and mode substitution effects. The study finds that the factors influencing ride-hailing services adoption include socio-demographic factors, perceived benefits, ease of use, safety risks and car-dependent lifestyles. The study also finds that integration of other transport modes with ride-hailing is weak. This implies that ride-hailing is mostly used alone in door-to-door journeys. 13 Question: How to construct a simulation model to assess the potential impact of automated mobility-on-demand on urban mobility such as its disruptive effect on urban transportation for travelers currently using mass transit or private vehicles? Results: Most studies on automated mobility-on-demand focus on the operational efficiency of the technology itself. The potential impact of automated mobility-on-demand on urban mobility such as its disruptive effect on urban transportation for travelers using mass transit or private vehicles need to be studied. The study [72] aimed to investigate the impact of automated mobility-on-demand on urban mobility. A flexible automated mobility-on-demand framework was developed for modeling/simulation based on SimMobility, a multi-modal agent-based urban simulation platform, which facilitates simulation of automated mobility-on-demand operations for different demand, such as mode choice, route choice and making trips.