Over the coming years, renewing traffic will, above all, be about making much better use of all kinds of traffic-related data. Data must flow smoothly and be compatible & interoperable between vehicles, different modes of transport, service providers and end users in order for us to create the strongest possible foundation for a sustainable transport system and new transport services and solutions. In a data ecosystem, data is exchanged between platforms using interfaces (APIs). In the traffic data ecosystem, we focus on traffic-related data, such as public transport schedules, traffic disruptions or weather conditions, with which service providers and application developers work together to create better customer experience and services. Those operating in the data ecosystem have a need for rules, as operators have a need to obtain data from each other. The fair data economy rulebook enables operators to better retain control over the data they share and decide on the related access rights and other business rules. The Rulebook is a tool for sharing increasing quantities of data either free of charge or for a fee, as agreed jointly. In practical terms, this will improve confidence in data integrity, quality, security, identity, operator roles and terms and conditions of use.