This Technical Specification defines the specific interfaces and functionality of traffic telematics (TT) services based on the use of cellular networks. Device manufacturers are enabled to develop terminal equipment compatible to services based on this Technical Specification. This will allow for interoperability of different terminal equipment and service providers which allows competition between service providers and terminal manufacturers. Furthermore it sets the scene for international availability of these services. This Technical Specification specifies -- TT-specific interfaces between terminal and service centre. This especially incorporates the message sets of the application data protocols and the service-independent communication handling (including conditional access and transport protocols). -- Functionality, procedures and requirements of basic terminal components as well as their interaction with the service centre. This especially comprises conditional access and security mechanisms. -- Service Specifications, which are essential to ensure consistent behaviour of terminal and service centre. The services incorporated within this issue comprise: -- breakdown and emergency services -- interactive traffic information services -- broadcast traffic information services -- navigation services (route assistance, route advice, homing) -- operator services -- general information services -- floating car data collection It is envisaged that future research and development will lead to improvements on the services listed above as well as to the creation of new services. Nevertheless this Technical Specification provides the framework for seamless integration of new features and services into the existing architecture.