Public Transport Acceleration Technologies

Trams and Buses communicate with traffic lights to get priority and ensure safety in different traffic scenarios. On different locations on the line, they send out a signal to the traffic light to communicate where there are currently located (pre-registration, registration, doors closed and doors closed). This is interpreted by the traffic light to change the order and duration of its cycles.

Different standards are used by different cities. Most notably the VDV standard. The image below shows what standard is used in major cities. The different section will list what city uses which standard.

VDV Standard

VDV (Verband Deutscher Verkehrsverbünde) standardized R09 Telegrams in VDV420.
They are sent out with a form of AFSK (FSK over FM) mostly in the 2m band. More information on how to receive this data can be found here.
Data contained in the telegrams is:
- Reporting point (Meldepunkt) containing an ID of the traffic light, some kind of information where the vehicle is located and its direction of travel. How a reporting point is "assembled" is not standardized and up to the transport company
- Optional: a line number
- Optional: a run number
- Optional: a destination number
- Optional: delay
- Optional: other fields used as the standard intends or for custom purposes
The table below shows different cities in Germany that use this standard.