Why is it important for lorry drivers to be able to see me in their mirrors?

I frequently see lorries with signs on the back which read, "If you can't see my mirrors, I can't see you" and my first thought is always "So what?". How does the driver knowing of my presence affect the way he drives his lorry? Or am I missing something?

Asked on 22 April 2011 by PB, Rochester

Answered by Honest John
It's simple common sense. If you 'hover' on the shoulder of a truck where the driver cannot see you, then you cannot blame him for moving into your path. Actually, vehicles simultaneously moving into the centre lane from lanes one and three is becoming more of a problem generally. Arrogant drivers in lane three often seem to feel they can dive into lane two with impunity, paying scant regard to vehicles moving from lane one to lane two. If drivers paid more attention to the impending needs of other drivers this sort of incident need never happen.
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