I've figured out that this consists of blearing your horn on the build up to and while overtaking...in single lane blind corners, up/down hills, regardless of whether you're a truck, car or motorcycle.
Oncoming traffic?? They'll just hear you and slow down. Or if it's 2 motorbikes, you just pass eachother in the one lane.
Crazy...i miss the riding, stopping off where i want etc, but glad to not actually have to drive!