Anyone interested in improving their observation and general thought processes when driving could do worse than get hold of a DVD called "Ultimate driving Craft" . Its presented by one of the top police Driving innstructors ,a guy called Chris Gilbert (he's the one who trained several members of the Royal family to drive )
It goes through the the ideas of hazard perception, commentary driving etc .
I got a copy off Amazon a while ago , about £20 , but worthwhile . ( NO I'm NOT on commission )