Traveling Salesman Problem with Path Flexibility Under Wireless Charging Lanes

Due to the limited battery capacity of electric vehicles (EVs) and the fixed locations of stationary charging stations (SCs), EVs typically require additional travel distance to be charged via SCs, resulting in a long time to complete given tasks in the context of EV-based urban logistics. Wireless charging (WC) allows EVs to recharge while traveling, potentially reducing travel distance, consumed time, and land use. This paper investigates a novel variant of the conventional traveling salesman problem (TSP) that incorporates path flexibility (PF) and wireless charging lanes (WCLs) to improve the service efficiency of EVs. The problem is formulated as a mixed integer programming model in which the travel speeds on WCLs are considered as multiple given options. The proposed model is NP-hard. We develop a dynamic programming (DP) algorithm (i.e., a labeling algorithm) to solve small-scale instances to optimality and heuristics for larger instances. The results of numerical experiments shows that i) WCL recharging mode outperforms SC settings in terms of total travel time because WCL allows EVs to perform on-the-go recharging, which is convenient and time-saving; and ii) PF and WCLs improve the accessibility of the recharging service, lowering the chance of battery run-off. Furthermore, we investigate the effects of recharging rate (i.e., technological factors) and WCL length (i.e., investment factors).