A review of Urban Air Mobility-enabled Intelligent Transportation Systems: Mechanisms, applications and challenges

The ground transportation systems have been applied and deployed worldwide. However, the growing urbanization and vehicular numbers are overwhelming the ground transportation systems. Pushing urban mobility into the third dimension with the potential to build a faster, safer, cleaner, and more comprehensive transportation system. Therefore, we believe that a solution will be found for the future of transportation from the three-dimensional perspective - the sky - which will revolutionize the way we perceive urban transportation - Urban Air Mobility (UAM). Owing to the features of UAM, such as autonomous maneuverability, convenience, mobility and communication, processing, and storage capabilities, that irreplaceability inevitably makes the UAM a key component of the Intelligent Transportation System (ITS). We state that human-centric remains the foundation of UAM. Key objective of this work is to provide an exploration of the imperative requirements to develop UAM and guidance for the research and development of UAM. In this context, we explore the mechanism of UAM in terms of definition, structure, reality, feasibility and key features and present the applications of UAM. Besides, we provide a systematic analysis of the challenges faced by UAM. Finally, we explore beyond technical issues that may hamper the research and deployment of UAM.