It is also important what is in the content/speedcam folder. It should be taken into account that different databases may have different speed data, and Here and TomTom maps may contain different speed data on a section of the road. Used *spc is also harmful, since it has speed for passenger cars and has priority over files speedcam.txt.
All this is important for using files called iTruck. It is also important to understand that any alerts may lag behind the actual traffic situation, and the speed limit may be temporarily limited. Road signs should always take priority over notifications from the navigator screen.