— Cooperative systems in transportation can bring new intelligence for vehicles, roadside systems, operators and individuals by creating a communications platform allowing vehicles and infrastructure to share information. The performance of this underlying communication system has a major impact on the effectiveness of the emerging applications for intelligent transportation systems. Similarly, the approach taken to the dissemination of relevant information throughout the vehicular setting is influenced by the network performance characteristics. This paper investigates the concept of data dissemination in a heterogeneous vehicular wireless environment. A communications architecture which consists of infrastructure based transmission for cooperative vehicular systems is described. Following this, a simple, policy-based solution to establish how best to disseminate the data for an envisaged ITS application is presented. This policy considers the application requirements and the qualit...