Recent research in UAV-assisted VANET architecture for smart cities focuses on integrating unmanned aerial vehicles with vehicular ad hoc networks to enhance communication reliability, scalability, and efficiency in dynamic urban environments. UAVs function as aerial relay nodes or mobile roadside units, providing real-time connectivity between vehicles and infrastructure even in areas with poor network coverage. These architectures utilize intelligent UAV placement, trajectory optimization, and AI-driven resource management to ensure continuous link availability and minimize latency during high mobility and dense traffic conditions. The collaboration between UAVs and VANETs supports critical smart city services such as emergency response, traffic control, and environmental monitoring through efficient data dissemination and adaptive routing. Energy-efficient communication models, blockchain-enabled security frameworks, and edge-assisted data processing are also incorporated to improve system sustainability, privacy, and responsiveness, making UAV-assisted VANETs a key enabler for next-generation intelligent transportation systems in smart cities.