In major cities, with the rapid urbanization and population growth, sustainable development has become a pressing global concern, leading to increasing traffic congestion, energy consumption, and environmental pollution. The transportation sector, responsible for nearly a quarter of global energy-related emissions, plays a vital role in addressing these issues. In response, numerous international frameworks have emphasized the need for cleaner, more efficient mobility solutions. In this context, shared mobility has emerged as a promising solution, bridging private car ownership and public transit to reduce emissions and promote efficiency. This thesis investigates two representative forms of shared mobility: electric vehicle carsharing (EVCS) and collaborative passenger-parcel ridesharing (CPPR), with a focus on operational optimization to support sustainable and economically viable urban mobility. The first two works in this thesis examine EVCS. The first study addresses station-based EVCS in a competitive market. A Generalized Nash Equilibrium (GNE) framework is formulated, where companies compete for limited infrastructure and user demand while jointly optimizing facility deployment, vehicle allocation, relocation, and vehicle-trip assignment. In addition, the study incorporates the role of government by proposing a bi-level model: the upper level represents the government's objective to maximize social welfare through infrastructure planning, while the lower level captures operator competition via the GNE framework. A surrogate optimization approach is adopted to solve the bi-level model, with an ADMM-based algorithm embedded at the lower level for efficient GNE computation. To further enhance carsharing flexibility, the second study focuses on free-floating EV carsharing systems with battery swapping (FEVCS-BS). Unlike the station-based mode, free-floating allows users to pick up and return vehicles at any location within the service area, offering greater convenience. However, this flexibility introduces operational challenges. The absence of fixed returning charging stations and the limited driving range of EVs makes vehicle relocation unavoidable for both vehicle recharging and rebalancing. To address this, two relocation strategies are considered: user-based relocation, driven by pricing incentives, and staff-based relocation, carried out by operational personnel. A mixed-integer nonlinear programming (MINLP) model is developed to capture users’ price-incentivized behavior and to jointly optimize hybrid relocation, fleet size, vehicle allocation, and trip assignment for profit maximization. An outer-inner approximation method with range reduction is applied to solve the nonconvex model and obtain a global optimum. Building on this foundation, the next two studies shift focus to another key form of shared mobility—ridesharing, where individual travelers with similar routes share a vehicle and split travel costs. However, conventional ridesharing often overlooks unused trunk space, missing the opportunity to fully utilize vehicle capacity. To address this inefficiency, we explore an innovative mode: collaborative passenger-parcel ridesharing (CPPR), which enables the joint transportation of passengers and parcels in the same vehicle. The third study explores the routing problem in CPPR while incorporating compensation affected passenger behavior. In this innovative mode, some passengers may be hesitant to share rides with parcels due to perceived inconvenience. Therefore, an effective compensation mechanism is essential to encourage participation. This study embeds compensation-related behavior into a routing framework and formulates the problem as a Compensation Scheme Design in a Split Delivery Vehicle Routing Problem with Time Windows for CPPR (C-SDVRPTW-CPPR). To solve it efficiently, a Surrogate-based Adaptive Large Neighborhood Search (SOT-ALNS) algorithm is developed to generate near-optimal routing plans. The fourth study extends the CRRP problem into a dynamic demand setting, where travel and delivery requests fluctuate throughout the day. Such an environment requires real-time decision-making while also ensuring long-term profitability. To tackle this, we formulate the Dynamic Vehicle Routing Problem with Time Windows for CPPR (DVRPTW-CPPR) and propose a Deep Reinforcement Learning (DRL) framework with a dynamic encoder-decoder architecture to learn optimal routing policies. In conclusion, this thesis explores the different shared mobility modes, including carsharing and ridesharing, to address critical challenges in operations. Through the proposed models and solution methods, operators can effectively manage operations, thereby supporting sustainability goals, and ensuring profitability of shared mobility services.
Read more