Transportation systems have come a long way, and are no longer stand-alone entities. This is due to the advancements in the various emerging technologies that enable Vehicle-to-Everything (V2X) communication. For example, one vehicle communicating with another vehicle on a vehicle-to vehicle (V2V) paradigm (e.g., to communicate traffic ahead, braking intention, lane changes, junction merges, etc.) and vehicle-to-infrastructure (V2I) where vehicles communicate with components such as traffic lights, street lights, signage, cameras, etc. The technology will become prevalent with the adoption of connected and autonomous vehicles and smart cities concepts in the near future. This will provide sustainable developments in transportation by enhancing safety and efficiency. This adoption of connected vehicles under the paradigm of intelligent transportation system will not come without challenges, and thus provides significant opportunities for emerging and novel research ideas. This Special Issue will focus on new advances and research results on vehicular networking, autonomous vehicles, sensor development and deployment, information fusion, decision making, traffic optimization, cyber security frameworks for the Internet of Vehicles (IoV), applications of 5G and beyond, etc.