Regarding the death of the girl, it wouldn't have mattered if the driver was doing 50 or even 40mph, if she wasn't lit up, she wasn't going to be seen at all. Her stupidity for walking down an unlit road.
On my route to uni I usually see a kid (who can't be more than 12) CYCLING to school along a busy 60mph "rural" road. What kind of stupid middle class twat parents send their young daughter to school on a bike on her own on a busy commuter route ffs?
Stupidly, stupidly dangerous! And a pain in the arse having to tiptoe past on the wrong side of the road as she weaves all over the bloody place too. Why is there not a minimum age or a test for cycling on public roads?
You're absolutely right, I reckon. It's amazingly poor judgement.
Regardless of speed limits, cycling on British roads, mixing it up with both white van man AND soccer-mom, is the equivalent of repeatedly kicking Murphy's law in the bollocks while shouting "wanna piece o' me?". Eventually he'll throw the book at you.
3,000 deaths per year out of 60 million road users isn't unacceptable at all, it's called natural selection.