Sustainable Shared Automated Fleets: Strategies for Integrated Operations with Public Transport

As the world undergoes rapid urbanization, with predictions that 68% of the world's populationwill be urban residents by 2050, the dynamics of urban transportation are undergoing a significanttransformation. Transportation network companies (TNCs) and shared autonomous vehicles(SAVs) are two important technological advancements within this transformation. One of the mostsignificant disadvantages of these technological services is their potential competing role withmore sustainable modes, such as Public Transport (PT), walking, and cycling. While PT is likelyto remain one of the most essential modes of travel because of its affordability and efficiency intransporting a large number of users in dense urban areas, SAVs may eventually lead to a declinein PT ridership and escalate urban congestion. However, if the operations of SAV fleets areplanned with the network, services, and ridership of PT in mind, these modes have the potential towork complementarily and increase the overall transport level of service experienced by users.This thesis presents an in-depth exploration of strategies to integrate the operation of SAVfleets with PT systems. The research critically examines the rise of SAVs and their role inaddressing inefficiencies in PT, such as long wait times and the demand for on-demand services.Furthermore, it underscores the importance of developing SAV dispatching strategies that are notonly efficient for the operation of this mode in isolation but are also integrated with the PT systemto maximize user access, equity, and sustainability.The thesis identifies significant knowledge gaps, including the need for a broader classification of dynamic dial-a-ride problem (DDARP) objectives under the Triple Bottom Line (3BL)approach of sustainability, including social, economic, and environmental dimensions. It alsounderscores an opportunity to enhance urban mobility by leveraging PT schedules for moreefficient ride-matching of SAVs. Therefore, this thesis identifies four primary objectives: 1)Categorizing DDARP objectives under the 3BL sustainability model, 2) Developing prioritizationstrategies for SAV ride-matching that enhance PT integration, 3) Formulating PT accessibility-based rebalancing strategies, and 4) Developing prioritized-based insertion strategies to improveboth SAV and PT service quality through strategic ride-matching.To achieve these objectives, this thesis first developed a novel framework categorizingDDARP objectives across the 3BL dimensions. Then, the thesis developed innovative ride-matching strategies for SAVs, prioritizing mobility-impaired trips and those without feasible PTalternatives. It introduced rebalancing strategies that enhanced PT reach by relocating vehicles toareas with high potential for First/Last-Mile (FMLM) requests and lower PT accessibility. Finally,it developed various insertion strategies prioritizing rides to improve the overall SAV servicequality and accessibility in areas with limited PT options. This thesis utilized the MATSimsimulation tool to evaluate these operational strategies within the Melbourne Metropolitan Area(Victoria, Australia), focusing on enhancing SAV operations.Implementing the proposed strategies in a simulated urban environment yielded promisingresults from a 3BL perspective. Economically, there was an observed increase in served rides andenhanced fleet utilization, particularly noticeable in the scenarios of undersupply of SAVs.Socially, these strategies significantly improved service efficiency and accessibility, especially inregions with limited PT access, thereby enhancing the equity of the transportation network andensuring a more balanced distribution of services. Environmentally, implementing these strategies reduced empty vehicle kilometers and overall vehicle travel, which are key indicators of atransportation system’s environmental impact and emissions, underscoring the strategies’alignment with broader sustainable urban development goals. Among the key findings, one of themost significant was the substantial increase in PT ridership and service efficiency in areaspreviously underserved by PT.The strategies developed in this thesis have significant implications for various stakeholdersin urban transportation: For users, they show enhanced service accessibility and quality, especiallyin areas traditionally underserved by PT. SAVs can integrate these strategies to evolve fromcompetitors to collaborators within the urban transport ecosystem and leverage these strategies toattract more users by improving service rates and eventually increasing their revenue. PToperators, through alignment with these strategies, can optimize their schedules and services forbetter alignment with SAVs, enhancing the entire transportation network's efficiency and PT’sreach. Governments and policymakers could leverage these insights to develop regulations andframeworks that facilitate SAV-PT integration, emphasizing sustainability, equity, and efficientresource utilization. In conclusion, the findings of this thesis highlight the practicality andeffectiveness of integrating SAVs with PT in achieving sustainable, efficient, and equitable urbanmobility, guided by the principles of the 3BL approach.