4. Before the downhill: rolling on.
Just before the slope, the driveline temporarily disengages, allowing the truck to roll. This saves energy, and minimises the need for braking.
5. On the downhills: braking in time.
I-See knows when the slope ends. Thus, when gaining speed downhill, it can apply the engine brake gently in time – instead of abruptly at the end – to prepare for the upcoming topography.
6. In the hollows: some extra schwung.
When a downhill is followed by an immediate uphill, I-See really comes to its right. It lets the truck roll, gaining speed and momentum to climb uphill with less effort.