I've always driven to the conditions of the road. And anyone who says they have never broken a speed limit is likely to being economical with the truth. Those same people slavishly obeying the speed limit (now 40)on what used to be our main roads also drive at exactly 40 when it's icy and foggy and I then find them sitting up my backside.
Generally it's bad driving that kills people. The speed cameras in Berkshire and Oxon are mainly placed to raise money not save lives. I slow down for horses and dog walkers, most of the above half asleep law abiding citizens don't even notice them.
The death rates on our roads are at the lowest rates ever but our obsession with the avoidance of any form of risk is crippling this country IMHO