Creating a smart city requires intelligent infrastructures and components. Smart transportation is one of the essential structures of a smart city that, by utilizing vehicular networks and data communications between vehicles and infrastructure, enables citizens to request high-quality services. However, the increase in these communications can lead to a decrease in network service quality. In this paper, an adaptive geographic routing method is proposed to establish a connection between two vehicles in a way that maintains service quality by creating a stable route despite increasing network load and vehicle mobility. To achieve this, three types of connections are considered: a multi-hop connection that only utilizes vehicles along the route, a single-hop infrastructure connection that seeks to connect source and destination RSUs, and a hybrid connection that leverages both types. The type of connection is selected based on mobility parameters and network load. The proposed method is compared with the most widely-used geographic routing in VANETs, namely GPSR, as well as its improved version, MMGPSR. Evaluation results indicate that the proposed method reduces end-to-end delay and also improves data delivery rate.