Can Platoons Form on Their Own?

Research on platooning has tackled many different facets of the topic, from lateral and longitudinal control to algorithms for optimization of platoon size and coordination. However, very few works started addressing the following two foundational questions. The first: Given a stretch of road where platooning is enabled and some form of V2X communication is feasible, will vehicles be able to organize locally in platoons without the need of central intervention? The second: Is a coordination protocol for platoon formation possible, or will traffic dynamics prevent the efficient formation of platoons? This paper gives a first, positive answer to these questions: A platoon formation protocol is proposed and tested upon DSRC communications, though it can be implemented on top of any transmission technology. We assess the performance in terms of platoon formation efficiency, on a multi-lane highway, as a function of the penetration rate of platooning-enabled vehicles and traffic characteristics. Realistic simulation results highlight the properties of the protocol as well as the impact of different traffic parameters, foremost the penetration rate and maximum distance between vehicles considered to start a platoon negotiation. These initial results pave the road for more sophisticated analysis, enhancements of the protocol and evaluation of advanced -possibly centralized- approaches to improve platoon management to achieve safer roads with increased capacity.