25-10-11, 03:47 PM
Ah, my mistake.
I did wonder if that was what you meant, but decided it couldn't be because the braking distance you achieved from 30mph comes out slightly greater than the highway code's quoted 14m (unless my maths is letting me down).
The highway code allows about two thirds of a second thinking time with good reason. Reaction time isn't quite the same thing, it might be easy to measure when you know what is going to happen and what you need to do, but often it takes a lot longer to analyse a situation on the road. I suppose that with experience our judgement improves and to some extent that compensates for slowing reaction times.