On the integration of shared mobility services in public and corporate mobility systems
Frank, Laura; Walther, Grit (Thesis advisor); Müller, Sven (Thesis advisor)
Aachen : RWTH Aachen University (2023)
Dissertation / PhD Thesis
Dissertation, Rheinisch-Westfälische Technische Hochschule Aachen, 2023
Private and corporate passenger mobility is still primarily covered by individually used cars. Given the environmental and social challenges caused by this car-centric mobility, the call for a transformation of the public and corporate mobility system is becoming ever stronger. While innovative shared mobility services like car or bike sharing promise great potential to address these challenges, infrastructural, market, and behavioral barriers still prevent a complete transformation to sustainable mobility. Only a systemic transformation of public and corporate mobility systems and coordinated planning of all stakeholders can fully exploit the potential of integrating shared mobility services to address the challenges of passenger transport. Against this background, this cumulative thesis presents four publications that provide a methodological framework for the strategic planning of the integration of shared mobility services in public and corporate mobility systems. The methodological framework is divided into two parts, with two publications each. One part focuses on the integration of shared mobility services in public mobility systems, and one part focuses on the integration in corporate mobility systems. Each part addresses two initial research questions: What is the potential of integrating shared mobility services, and how can these services be optimally integrated? A prolog and epilog frame the cumulative thesis by presenting and discussing the aim of the thesis, the context of the publications, and the current state of related research. The first part of this thesis addresses the integration of shared mobility services in the public mobility system. In this context, the aim is to analyze how an intelligent integration of shared mobility services may support public transportation, i.e., how these services can help to improve the accessibility of public transportation by enabling intermodal travel behavior. The first and second publication of this thesis contribute to fulfilling this aim as described in the following: The first publication presents a quantitative methodology to evaluate the quality of public transportation. By comparing the mobility demand with the supply of public transportation, the methodology identifies critical connections and classifies them according to the need for action. The methodology serves as a primary analysis to gain insights into the public transportation system's weaknesses and provides a transparent planning base for integrating shared mobility services. We apply the methodology to a case study in a rural area in Germany in which we identify critical connections to places of daily need and to workplaces. The second publication introduces a decision support tool to plan the strategic integration of shared mobility services at multimodal mobility hubs. We present a mixed-integer optimization model that simultaneously provides decisions on hub locations, hub composition concerning available shared mobility services, and the required infrastructure, e.g., parking spaces, charging stations, shelters, and signage. The model maximizes the accessibility of the integrated public mobility system while meeting the budget constraints. To account for a systemic transformation, the approach considers interdependencies between public transportation and shared mobility services by enabling new intermodal travel itineraries. Finally, in a real-world case study, we derive managerial insights on the integration of shared mobility services, e.g., regarding the cannibalization of public transportation. The second part of this thesis addresses the integration of shared mobility services in the corporate mobility system. In this context, the aim is to analyze how an extension of traditional company-exclusive mobility services by public shared mobility services can help to improve the efficiency of corporate mobility. The third and fourth publication of this thesis contribute to fulfilling this aim as described in the following: The third publication provides a quantitative methodology to evaluate the potential of an overall fleet size reduction. Herein, we investigate an integrated car sharing system for private and corporate user groups, which uses pooling effects within each group but also between both groups. Given the complexity of the spatio-temporal distribution of mobility demand and vehicle supply, we develop an integer optimization model to compare the minimum fleet size of an integrated system with the size of separate fleets. In an exemplary case study, we quantify the potential fleet size reduction for an integrated car sharing system in Munich. The fourth publication presents a decision support tool to plan the strategic integration of shared mobility services in the corporate mobility system. Based on an integer optimization model, decisions on the fleet size and composition of corporate fleets are derived. The methodology accounts for interdependencies with the public mobility system by shifting parts of the demand to shared mobility services. Further, the model provides decisions on the choice of memberships in these services based on the offered price tariffs. The approach minimizes corporate mobility costs while meeting all structural requirements, such as technical vehicle restrictions and the acceptance of micromobility modes, like bikes and scooters. Finally, we apply the methodology in a case study with driving profiles of 144 companies to derive general insights into the current and future potentials of a multimodal corporate mobility system.
- Chair of Operations Management