Just to add to the speeding talk for a motorway this is not as valid to an extent but the speeding limit's at set as an assement of the road not just the driver's on it and part of that assement is what is on the road if you hit someone at 30 miles an hour and it's there fault i.e. they ran out into a road chasing a ball say they are more likely to survive it while if you where driving at 50 they are a lot more likely to die.
Previous post's have said there is a differene betwen driving safely and speeding there is but the speed limit is set both because of the road conditions where you are and also what's on the road school house's ect.. that you might come into contact with. If your speeding your speeding however you justify it.
Cake, the exact point Crashie was making was that schools don't get out and kids are not chasing balls at 3am but the limit doesn't change whether you are going past at school kicking out time or in the middle of the night, but clearly one is much worse than the other.