The VANETs are a prominent part of intelligent ITS, as it enables smart wireless communication among roadside vehicles. The VANETs assure efficient migration of roadside traffic and operate the VANET users safely by adopting various wireless technologies, application services, and wireless standards. The VANET routing protocols enable smart communication among vehicles and roadside units. The VANET routing protocols are mainly categorized into three types that are topology-based, geographic-based, and hybrid. The multi-hop routes, large network size, communication device heterogeneity, congestion, and constrained network bandwidth are the major challenges faced by VANET routing algorithms.