As explained above, we distinguish between two categories of traffic streams in vs | plus:
- The first type of traffic stream involves a single or multiple traffic participants. It is not known how large the total volume is. This category can be signalled by a single road user in the red. If the assigned signal is green, this can be extended by any road user. These are generally motor vehicles, bicycles, pedestrians, etc., everything that belongs to individual traffic (IT).
- In the second category, individual vehicles are followed from the first signal until they pass the stop bar. Vehicles can log on and off. In vs | plus you always know how many vehicles still need to be processed. Typical types are local public transport, ambulances, police and emergency services. As this type of request is mainly used by public transport, the short form here is PT. Each of these vehicles must be equipped with the technology that allows the control unit to detect the vehicle.