Rather than engaging in a tiresome post slicing exercise I'd simply observe that most of what you have pointed out, whilst essentially true in its own right, does not concern itself with the core issue of 'naming names'.
DeltaF wrote:
Crash barriers etc are PROVEN, no shadow of doubt, to do what they say on the tin, reduce accidents and fatalities and injuries.
In which case, trying to maintain the a line of discourse consistent with the original proposition, you should be able to provide me with the list of the names of those whose lives a crash barrier has saved.
I am reminded of an episode of the Simpsons, where all of life is actually enacted in cartoon form

. The citizens of Springfield have marched on city hall to demand that mayor Quimby do something about the bear 'attacks' - there having been only one bear in the town in living memory. So Quimby starts the Bear patrol.
Scene shifts to outside of Homer's house where Bear patrol trucks, helicopters and stealth bombers are whizzing by.
Homer: Ahh, the Bear Patrol is working perfectly, not a bear in sight.
Lise: Thats specious reasoning dad
Homer: Thank you honey
Lisa (picks up rock): By your logic I could claim that this rock keeps away tigers.
Homer: Hmmm, how does it work?
Lisa: It doesn't. But I don't see any tigers around here do you?
Homer: Lisa, I want to buy your rock
Lisa: No, no......(sighs, takes money and gives Homer the rock)
As Lisa says, the presence of the Bear Patrol does not prove that it has helped keep away bears. Likewise, the fact that there aren't any bears doesn't mean that the Bear Patrol hasn't help keep them away.
Similarly, not being able to name specific names does not mean that speed cameras havent saved any lives. Granted, they may be very few in number and the way in which those live have been 'saved' may be quite subtle.