Vehicular Networks in the future will involve a major revolution for safety and comfort of road transport. In these networks, warning messages affect decisions taken by drivers, so it is necessary the existence of a scheme to determine whether the road traffic information available to the driver is trustful or not. Besides, the quality of communications is degraded when the number of non cooperative vehicles is very large. For this reason, cooperative groups are proposed as a solution to the spread of false traffic warning messages, and reputation lists are presented to stimulate cooperation among selfish nodes.
