TrendSharing: A Framework to Discover and Follow the Trends for Shared Mobility Services

With the development of ubiquitous smart devices, shared mobility services, such as food delivery, ridesharing and crowdsourced parcel delivery, and the related problems, such as task assignment and route planning have drawn much attention from academia and industry. Specifically, shared mobility services enable one worker to deliver more than one package/passenger together such that their routes can share some common sub-routes. Tardiness (the exceeded time) can harm users' experience and reduce the revenue of workers and platforms, which is not well handled in the existing studies. In this paper, we propose a framework, TrendSharing, to minimize the total tardiness when serving all tasks. In TrendSharing, we first build a flow tree to group tasks together. Then, we propose a concept of trend, which represents a group of tasks with high sharability in the flow tree. Furthermore, we devise a decision factor$\epsilon$-score to properly select the trend from the flow tree. In addition, we devise an indicator k-regret to quantify the likelihood of tardiness for each task and devise a greedy algorithm to conduct task assignment. We observe that the insertion operation that is widely used by existing works has little effect on the objective of minimizing total tardiness. Thus, we adopt a simple yet effective strategy, which will continuously append newly planned routes to the workers' existing routes. Moreover, we design an algorithm to plan a route for the trend with an approximation ratio of 2.5. Through extensive experiments, we demonstrate the efficiency and effectiveness of our proposed approaches on real datasets.