Flashing your headlights

[Newell Attack]

I know that it's helpful to truckers to have the vehicle they just passed flash his headlights to show that it's safe to pull back in to the right-hand lane, but here is my question: Is it correct to flash your headlights BEFORE the passing vehicle puts on his right turn signal to show his intention to pull back in, or IN RESPONSE TO his signal, as if to say, "OK c'mon back in"?

Jeff

[Randy J]

It's okay to flash and say come on back over rover.

[The Newell]

I could usually can see the driver in the mirror so I just watch for him/her to look then flash my lights if they're clear.

[speedingsport]

You can quickly flash your headlights when you see the semi trailer clears your coach and there is room for him to move back into the driving lane.