Optimization of Highway EV Charging Infrastructure Considering Station Attractiveness and User Equilibrium

Abstract

The growing adoption of electric vehicles (EVs) has created an urgent need for efficient and user-friendly charging infrastructure. While many studies focus on minimizing costs and travel times, they often overlook the influence of station-specific factors, such as amenities and user preferences, on charging behavior. Given EVs’ shorter driving range and longer charging time than conventional vehicles, it is essential to focus on the charging demand of EV users traveling long distances and their value of time during charging. This necessitates addressing the deployment of charging stations in highway networks, considering location attractiveness among EV users. This study proposes an optimization framework for deploying EV charging stations along highways, emphasizing the role of station attractiveness and its impact on user route choices. The model uses a bilevel optimization approach, combining infrastructure planning with user equilibrium (UE) principles to reflect real-world travel and charging behaviors. A multiserver (M/M/c) queueing model is used to estimate expected waiting times at charging stations, and the resulting waiting-time term is embedded in the generalized cost in the UE-based assignment, enabling charger sizing decisions that reflect demand–capacity interactions. A numerical example is used to examine the impact of station attractiveness under different scenarios. Then, a case study on Taiwan’s national highway network demonstrates the practical benefits of incorporating station-specific factors, leading to improved user experience during charging and resource allocation. These findings highlight the importance of considering station heterogeneity in charging infrastructure planning.