"UK official stopping distance at 30mph is 23m, if a small child runs out into the road 1m in front of my car then it may be my responsibility to avoid them but the laws of physics disagree."
It was your responsibility to see them at the side of the road, or to see that you couldn't guarantee that there was no-one there, and adjust your speed accordingly.
Thus changing the 23m stopping distance into something much more reasonable, and starting at a speed which is far less likely to kill said small child if you still fail to avoid the collision.
Biting the hand that feeds IT
