Creating a trigger when material ceases running on a belt

[Impatient]

Regarding showing what is the current throughput on a belt, you might be looking for the "running average" or "moving average".

viewtopic.php?t=51471

[BlueTemplar]

If you weren't so Impatient, you would have seen that this post has already been linked.

You could limit yourself to one yellow lane, or even slower using inserters/circuits.

I myself have been using a setup that dynamically shuts down the miners of a field :
- initially, depending on the fraction of the ore field that they cover (adjusted for ore density)
- then, depending on train chests fill rate