Applications of Vehicular Ad Hoc Networks (VANETs) in the service of Intelligent Transportation Systems (ITS) have received much attention in recent years, which also has brought new challenges. Clustering is known to reduce the overhead of wireless communication in Mobile Ad Hoc Networks (MANETs) and provides an efficient hierarchical network structure. In this chapter, we propose a Directional Stability-based Clustering Algorithm (DISCA) especially for VANETs which takes direction, mobility features, and leadership duration into consideration. DISCA is distributed and enables the formation of stable clusters. An efficient cluster maintenance procedure adaptive to high mobility is also presented. Simulation experiments are conducted in a realistic vehicular network model to determine which algorithm provides optimal stability over the simulation timeline. The results show that DISCA significantly improves cluster stability. In addition, a DISCA-based broadcasting protocol is proposed to further validate the effectiveness of DISCA, and as a result it significantly reduces the number of rebroadcasts, while improving the reachability and latency in comparison to other protocols.