A priority-based smart queuing technique for congestion management of IoT-enabled EV charging stations

The increasing adoption of electric vehicles (EVs) places growing pressure on public charging infrastructure, where congestion and prolonged waiting times can adversely affect service responsiveness and charging-station operation. This paper presents a priority-based smart queue management framework for IoT-enabled electric vehicle charging stations (EVCSs). The proposed framework integrates vehicle-category priority, battery state-of-charge (SoC), reservation status, congestion-aware station assignment and reallocation, bounded deferral, and dynamic pricing to support differentiated charging service while maintaining infrastructure utilization and grid stability. A heuristic scheduling mechanism is employed for computationally efficient implementation of the underlying optimization formulation. The framework is evaluated using a publicly available synthetic EV charging dataset under a controlled simulation environment and compared with First-Come-First-Serve (FCFS), Static Scheduling, and SoC-Based Priority Scheduling. To account for stochastic variability, the evaluation is conducted over 30 independent simulation runs using matched workloads across the scheduling methods. The proposed method achieves a mean waiting time of 133.87 min, compared with 177.42 min for FCFS, 176.88 min for Static Scheduling, and 177.75 min for SoC-Based Priority Scheduling, corresponding to reductions of 24.55%, 24.32%, and 24.69%, respectively. Paired statistical tests confirm significant waiting-time reductions for all three comparisons ( p < 0.001 ), with large paired effect sizes. The proposed method also maintains infrastructure utilization and grid-stability characteristics broadly comparable to the considered baselines while providing differentiated service across user priority categories. These results demonstrate the effectiveness of the proposed framework as a computationally lightweight approach for congestion-aware and priority-sensitive EV charging management.