Originally Posted by
Paul Barnard
I apply the 3 D's irrespective of my mode of transport.
Is it dumb, dangerous or discourteous? Is so, I don't do it. If not, then it's all good.
Never thought about it in those terms, but that's a pretty good rule of thumb.
And although that might not always keep one strictly within the letter of the law, it will tend to keep one sufficiently within the spirit that sanctions are unlikely.