Two-sided subsidy design for urban EV charging infrastructure planning with spatially feasible candidate sites

The growth of electric vehicles has made charging infrastructure a key component of urban transport electrification. However, market-driven deployment may concentrate stations in profitable areas, leaving peripheral demand insufficiently served. This study develops a government-operator bi-level planning model for mechanism-differentiated operator- and user-side subsidies. Station siting is restricted to a spatially feasible set of parking-lot POIs identified through land-use, road-accessibility, and prohibited-area screening. Within this candidate set, the government optimizes tier-based two-sided subsidies by balancing user generalized cost, fiscal expenditure, and spatial equity. The lower level determines station construction and capacity decisions. User choice incorporates an outside option and waiting-time feedback. The model is solved using a nested PSO-SA algorithm and applied to Jiangbei District, Chongqing. Results indicate that operator subsidies more effectively expand capacity, while user subsidies improve accessibility. By coordinating supply expansion and demand guidance, the two-sided scheme attains the highest upper-level objective under benchmark weights.