The rideshare matching problem and its generalized forms have been investigated extensively in the field of operations research (see e.g., Özkan and Ward 2020; Hu and Zhou 2022; Lowalekar et al. 2018 and the references therein). Typically, both the open trip requests and available drivers are batched within time windows of fixed length as they arrive at the system, and they are matched at predefined discrete review times. See Fig. 5.1 for an illustration. Hence, ridesharing matching is an online stochastic problem (Qin et al. 2020a). (See Sect. 5.1 for a mathematical formulation.)