it makes me wonder if they either have too much time on their hands or are driving slow because they are trying to hide the fact they are drunk
wanna travel at 15mph get a bloody bike[/quote]
You two arguing again ?

Gonna' have to get a guidance counsellor soon ! Will have to mediate.
Point is, how low a speed limit do you go before absolutely safe for pedestrians stepping out in the road ? Almost standstill, I guess. All about anticipation at the end of the day.
Chav is correct here, they usually are unsure drivers or drunk or very elderly (notice I use 'very' to absolve myself). Neil is also vaguely correct in that you don't have to drive at 30 m.p.h., but come on, Neil, betta' ya' you have gritted your teeth occasionally behind someone driving so slowly. it's dangerous, aint it ? Because you don't know what they are going to do next.