In the near future, our streets will be populated by myriads of autonomous self-driving vehicles to serve our diverse mobility needs. This will raise the need to coordinate their movements in order to properly handle both access to shared resources (e.g., intersections and parking slots) and the execution of mobility tasks (e.g., platooning and ramp merging). The aim of this article is to provide a global view of the coordination issues and the related solutions in the field of autonomous vehicles. To this end, we firstly introduce the general problems associated with coordination of autonomous vehicles by identifying and framing the key classes of coordination problems. Then, we overview the different approaches that can be adopted to deal with such problems by classifying them in terms of the degree of autonomy in decision making that is left to autonomous vehicles during the coordination process. Finally, we overview some further research challenges to address before autonomous coordinated vehicles can safely hit our streets.