Traffic is one of the most important problems in industrialized countries: roads are getting more and more crowded, especially during rush hours, with heavy consequences on people’s quality of life, accidents, pollution, and fuel consumption. The transmission of up-to-date traffic information to on-board navigators would allow the redistribution of traffic flows over alternative routes, thus reducing road congestions and slowdowns. In this paper we investigate the possibility to send the information on the average-speed in any road of interest to on-board navigators by means of current broadcast and unicast communication technologies. A discussion on the most convenient transmission strategy will also be given with reference to real scenarios.