<p>The traditional truck-based delivery systems often face challenges such as traffic congestion and increased emissions due to frequent stopping and idling; these issues lead to delays and contribute significantly to environmental pollution. This paper explores Drone–Truck combined operations (DTCO) as an alternative approach to mitigate these challenges. By integrating clustering techniques and optimization algorithms, the study aims to improve delivery efficiency while reducing the environmental impact. The effectiveness of the DTCO model was evaluated based on CO₂ emissions and delivery time across varying workloads. The results indicate that our DTCO model reduced CO₂ emissions by an average of 44.75% and delivery time by 22.8% compared to a traditional truck-only model. The system remained scalable as we continued to see efficiency gains across varying delivery volumes. These findings indicate that DTCO shows potential to provide a scalable and environmentally sustainable alternative for last-mile delivery logistics. By reducing truck dependency in congested areas and leveraging drones for last-mile deliveries, this approach enhances operational efficiency while lowering emissions.</p>