Recent research in routing protocols for smart city environments in Vehicular Ad Hoc Networks focuses on developing intelligent, adaptive, and context-aware communication frameworks to support efficient data delivery in dense urban traffic. Advanced protocols integrate artificial intelligence, machine learning, and bio-inspired optimization algorithms to predict vehicle mobility, optimize path selection, and minimize communication delay. Researchers are also incorporating software-defined networking, fog, and edge computing concepts to enable real-time route adjustments and load balancing across smart city infrastructures. Security and privacy are being enhanced through blockchain-based routing and trust-aware models that ensure reliable data exchange among vehicles and roadside units. Overall, these innovations aim to provide scalable, secure, and energy-efficient routing solutions that enhance safety, traffic management, and intelligent transportation services in next-generation smart cities.