I'll do 30 in the 50 area if that's the safe speed to do - it's 50 outside our local shops and the place is crawling with children who leap out from behind cars.

TBH I like to think of the speed limit as a rough guide

People need to drive to the conditions and sometimes the conditions and the speed limit appear to contradict each other.
Of course. But when it is an open st, with no obstructions, no risks, nice sunny day, no people around. Drive at speed limit. Not that hard to do.
Our main st is 50kms, but it is totally not possible to ever drive at that speed through there. With cars parked on both sides of the road. Then the crossings, lights, people crossing whenever they like. Well of course you are lucky if you ever hit 30kms safely.

You definately neet to drive to conditions, but when you are driving at an extremely low speed when it is not needed then that is dangerous. I always adjust my driving to accomodate the enviroment, the other drivers around me, environmental risks and all that stuff, but that doesnt mean I should always drive 10+kms below the speed limit.