I don't normally have trucks passing me, but when I pass them, depending on the truck, they normally get pushed away when I am about 1/3 next to them. I have to watch if they react, because when they do, it is easy for them to over correct, at the same time the air pressure equalizes. Normally they don't get sucked into my lane till I am nearly past them. The big long trucks I don't worry about much, but I am much more careful around other RVs, especially trailers. If I can't give them a lot of room, I slow down as I go past, so they don't get thrown.