ITS services are the result of specific value chains varying according to the specific service - but with the same basic functionalities. The figure below presents a generic value chain for travel and traffic information services - but it applies to most ITS services. Each of the functions in the value chain specifies a responsibility for carrying out a specific task - and that responsibility is assigned to one or more of the organisations involved.
The roles of road authorities and other public sector stakeholders differs depending on the ITS service in question. Typically, road authorities have a more prominent role in services related to their core business of network operations, such as freeway management, traffic management, and incident management. They do not, though, have any major role in most vehicle based systems - such as driver support systems. In addition to the roles in the value chain, the public sector is always responsible as the regulator for any regulations or legislation setting out the legal framework for ITS service provision.
The roles of different stakeholders - and the borderline between public and private stakeholders - varies depending on national organitaional cultures and traditions. In some countries, the public sector stakeholders have responsibility for most parts of the value chain - such as real-time traffic event information services - whereas in other countries, the public sector is only involved in providing data for these services.
There is no single correct model of division of responsibilities for ITS services. Each ITS service has its own value chain or network, and the roles and responsibilities are determined by the local organisational cultures, tradition, conditions, markets and economic situation. Sometimes, the public sector needs to take a more active role than expected - such as when the private sector will not, by itslef, provide a socio-economically beneficial ITS service in areas of the public sector's jurisdiction.