When traffic lights give drivers speed recommendations and the driver follows them, this reduces fuel consumption. This is demonstrated by systems such as the Green Light Optimised Speed Advisory (GLOSA). How this can work was tested as part of the "Real Lab Hamburg" projects. The focus of the project was not only on passenger cars but also on cyclists and e-scooter drivers.
At the ITS World Congress 2021, the Traffic Light Assistant from T-Systems was presented as an Android and iOS app. The app provides phase and forecast information on traffic lights in the test field for automated and connected driving (TAVF) in Hamburg. The traffic light assistant processes both location-based and map-based information for this purpose. It determines the traffic light systems relevant for the user based on his or her position and driving direction. The service then informs about the current signal phase of the next traffic light combined with a forecast for the next phase change.
The data of the traffic light systems are forwarded from the central servers, for example the manufacturer cloud of Siemens and from a transfer point of the operator of the Hamburg Verkehrsanlagen (HHVA) to the 5G edge server of Deutsche Telekom. Several edge servers are distributed across Germany to provide short connections between user devices and applications. An edge server is also available at the TAVF in Hamburg.
The data exchange format is the European standard ETSI ITS for Signal Phase and Timing (SPaT) and MAP (Topology Information of the Intersection) messages as well as CAM (Cooperative Awareness) messages.
The collision warning function from Continental AG is also integrated in the Traffic Light Assistant app from T-Systems. This calculates possible future collisions of road users based on the position and trajectories of several users in a so-called accident hotspot (e.g. at an intersection). Road users are warned in a timely manner before colliding with other road users or are alerted to unavoidable collisions with an emergency warning.
More about the Traffic Light Assistant: