There's something very moral about doing your best to prevent serious overtaking accidents once you've managed to recognise that human beings behind the wheel can be impatient and inclined to take risks when, as they see it, they're stuck behind you. To take your argument into the absurd, you might as well say that you're aiding and abetting speeding by staying at home to watch the telly instead of going out in your car when you could be leading a convoy. It's safer all round to pull over and let them pass.

As for speed limiters, well it's four miles from my house into Bude. The speed limits on that route are 20, then 60, then 50, then 30, then 40, then 30. On the way home, the same in reverse. I'd be interested to hear how your speed limiter would handle that.