Geoff,
That just don't speed line, does not cut it. What could be a fair way to improve safety is manifestly used for revenue raising and has little bearing on road safety.
We have lower limits on the open road in many places than 30 years ago. Cars are far safer but they treat us all as morons and cash cows.
We spend to much time worrying about 5 different speed zones on a 3 km stretch of road-(none of which make apparent sense) than what is going on outside the car. This causes accidents and lots of them, sticking to a arbitrary speed number does not make you safe. Driving properly for the conditions does- that includes eyes on the road not staring at the speedo.
Cars are driven by VFR not IFR but the rules push us to IFR.
Speed has never killed anyone, it is excessive speed for the conditions.
Some research has even showed artificially low speed limits do actually kill. Drivers get distracted easily, bored,tired and make fatal mistakes. They get lulled into a false sense of safety- hey I am at the limit so must be safe. OR they get frustrated and overtake dangerously and bang.
If we drive to the conditions of the road,traffic,the car and our ability- we are focused on the job-driving safely.
To say just follow the rules, is a very simplistic view for a complex issue.