The frame signal plan results from the sum of the frame signals. Just as the signal times of the signal groups form a signal time plan in conventional technology, the frame signals of the traffic streams form a frame signal plan. It is essential that the sum of the frame signals corresponds to the sum of all traffic streams and not the sum of all signal groups.
As a rule, the frame signals are planned based on the signal times of the fixed time control. By separating the frame signal into a registration and extension area, it is avoided that a signal group assigned to the respective traffic stream switches the green time outside the frame.
The control principle is defined with the construction of a frame signal plan. A control system with consistent coordination in the conventional sense or a coordination system with passive and active green band widening or even a fully traffic-dependent control system can be determined.
From the perspective of VS 2, there are the following areas:
- Passive green band extension: The green start of the traffic stream (VS 2) is determined by the green end of the conflicting traffic streams (VS 1). The conflicting traffic streams can extend with traffic to the end of their frame.
- Coordinated green band: In this area, the green of the traffic streams cannot be cancelled by conflicting traffic streams. The green of the traffic streams is protected.
- Active green lane extension: A conflicting traffic stream (VS 3) has a frame. As long as the traffic stream (VS 2) still has traffic, it can extend to the end of its frame.
Figure 11: Frame signal plan for fully traffic actuated operation
If all frame signals are always enabled, this results in full traffic-dependent control. Depending on the design of the framework plan, this results in full traffic-dependent control or fixed coordination or mixed forms such as traffic-dependent coordinated partial traffic dependency.
Figure 12: Frame signal plan for coordinated actuated operation
Some traffic streams have a restricted area for call and extension that can overlap with conflicting traffic streams. Other traffic streams have a permanent frame. In the areas where hostile traffic streams overlap, there is a partial traffic dependency.
Figure 13: Frame signal plan for coordinated fixed time operation
In this example, there are no overlapping areas. The traffic streams can only log on and extend in precisely defined areas. There is no traffic dependency.