In my opinion some of this is simply due to how congested built up areas are today. It's genuinely hard to get up to 30 in a city or any populated area in the UK today, and most cities in the UK now have 20mph speed limits when there's likely to be pedestrians around.
It's pretty hard to kill people if you're driving under 30, and anywhere people are driving in excess of 30 it's not that populated and cars these days are pretty safe unless you have a head on collision at significant speed.
It's pretty hard to kill people if you're driving under 30, and anywhere people are driving in excess of 30 it's not that populated and cars these days are pretty safe unless you have a head on collision at significant speed.