###### Abstract  
Vehicular Ad Hoc Networks play a crucial role in enabling Smart City applications by facilitating seamless communication between vehicles and infrastructure. This study evaluates the throughput performance of different routing protocols, specifically AODV, AODV:TOM, AODV:DEM, GPSR, GPSR:TOM, and GPSR:DEM, under various city and highway scenarios in complex networks. The analysis covers key parameters including traffic generation, packet sizes, mobility speeds, and pause times. Results indicate that TOM and DEM profiles significantly improve throughput compared to traditional AODV and GPSR protocols. GPSR:TOM achieves the highest throughput across most scenarios, making it a promising solution for high-performance data transmission in Smart Cities. For instance, GPSR:TOM achieves an average throughput of 3.2 Mbps in city scenarios compared to 2.8 Mbps for GPSR, while in highway scenarios, the throughput increases to 3.6 Mbps. Additionally, AODV:DEM records a throughput of 3.4 Mbps for high traffic generation, outperforming AODV:TOM at 3.1 Mbps and baseline AODV at 2.7 Mbps. The findings highlight the importance of optimizing data throughput to ensure reliability and efficiency in complex vehicle interconnection systems, which are critical for traffic management, accident prevention, and real-time communication in smart urban environments. title=1, description=Aterms of network scalability and data throughput. As the number of connected vehicles and devices increases, managing large data volumes with low latency becomes difficult [2]. High data throughput is necessary to ensure that vehicles can transmit and receive information in real time, enabling applications such as collision avoidance, traffic management, and autonomous driving [3]. Without adequate throughput, delays in communication can lead to safety risks and traffic inefficiencies. Solutions like 5G networks and edge computing can improve data transfer rates and ensure the reliability of vehicle interconnection systems in urban environments [4]. Moreover, major Quality-of-Service (QoS) aspects such as reliability, connectivity, packet loss, and delay remain as open research issues. For example, providing continuous connection to a vehicle node imposes real challenges because of mobility, the variations in network topology, and frequent changes in traffic conditions, which create different network performances [5]. These deviations may deteriorate network performance. Thus, mitigating the impacts of these problems is a matter of real-life importance. On the other hand, achieving a stable level of performance in vehicle interconnection is a challenging problem. Practically, vehicles tend to travel long distances. As a result, a vehicle may be attached to different network scenarios and topologies [6]. This unique behavior in vehicle interconnection brings attention to robust routing protocol design [7]. For example, a vehicle that runs the same routing protocol, while it moves from one geographical area to another, it experiences different network topology requirements, and thus, the performance of the routing protocol contrasts. Consequently, the performance of the network drops [8]. One of the main goals of vehicle interconnection is to exchange information messages between vehicles (V2V) and between vehicles and the infrastructure network (V2I) [9]. To accomplish this feature, packets move in a multi-hop fashion to their target node (destination), where a routing protocol is responsible for (1) finding the path to the destination, (2) and, in case of multiple paths existing to the destination, the routing protocol must select the optimum path among existing ones [10]. The dynamic nature and the wireless connectivity of VANETs increases the complexity of designing a routing protocol to accomplish the adhered tasks [11]. Recent developments in the field of Vehicular Ad Hoc Networks have led to a renewed interest in this open research area, which plays a crucial role in shaping the communication infrastructure of Smart Cities [12].