Intersections equipped with sets of traffic lights are necessary parts of urban road networks. They essentially impair the quality of traffic flow in cities. An effective control of traffic lights on the one hand and an increased acceptance of road users as a result of more information on the other hand are the basic principles for a good symbiosis. Other than conventional detectors the so-called co-operative systems in transport offer the opportunity for an extensive collection of detailed information on traffic conditions via Floating Car Data in order to optimize the control of traffic lights. Furthermore, road users can be kept informed on switching times or on their virtual position in the green wave. The paper focuses on the communication between vehicle and infrastructure (V2I) and on the algorithmic processing of vehicle and traffic light information using on-board nomadic devices.