Everything red
Alles-Rot is a type of signal control on traffic lights , a distinction is made between two variants.
Variation I.
All roads leading to it and the pedestrians always have a red signal. When a direction is requested (pedestrians via push button, motor vehicles via induction loop ), the signal program can switch a release for the requested traffic direction without an intermediate time. The waiting time after the request is significantly reduced. This variant is used for signal systems with little motor traffic and a lot of pedestrian traffic.
The short switching time after the request is the main advantage here, but there are a number of disadvantages:
- All road users have to wait first.
- The establishment of requirement systems in all tributaries is necessary.
- With frequent requests, there are longer waiting times and the system is controlled depending on the traffic.
- There is a risk that the red signals are often ignored by road users.
Variation II
When pedestrians request it, vehicles in all directions are shown red. In this way, conflicts between pedestrians and simultaneously released turns, i.e. accidents, are prevented, but this also results in additional shift phases and therefore a long trip with little performance. This variant is also known as all-round green for pedestrians. A common variant of this is diagonal crossing . Here pedestrians can also cross the intersection diagonally.
The disadvantage is that longer clearing times for pedestrians (time in which all pedestrians have left the intersection) must be provided. This variant is suitable when there is heavy diagonal crossing traffic and therefore longer waiting times for pedestrians are generally avoided.