As stated,Peter,an AWARE driver would know that 2-3 flashes of the right indicator meant that the truck driver ahead believed that it was safe to consider an overtaking manouvre.If the following driver was ignorant of this,they certainly wouldn't try overtaking a truck that they thought was turning right,surely? The usage of indicators is only an aid to those who understand the process,and would have no effect on others.Cheers
2 to 3 flashes on a right indicator clearly means I am going to turn to the right. Giving it any other meaning seems totally illogical and dangerous to me.
Clearly it can be and is misunderstood and it is against the law. That should be enough to stop this practice.
In Europe there is a similar convention and it is EXACTLY opposite that practiced in this country.
I avoid giving other drivers any "suggestions" as to what they might or might not do although I once blocked an overtaking vehicle by moving across the centre line of the road because I could see an oncoming vehicle that he could obviously not see.