Because the schools tend to be on streets where kids play, near homes, and on smaller streets where cars still manage to be ragged about whereas camera's always seem to be on straight, duel carriageways or ring roads. I'd rather the cars around where I live were slowed down than those on ring roads etc As i said most of the time cars cant really do much speed around these areas, but also kids should be told about maybe not playing on a public highway and how to cross a road! But i would happily concede to this if they actually put proper limits on other roads out of towns and housing estates etc! But main point rather have speed cameras than sneaky cops in unmarked vans!