If 10,000,000 vehicle trips use a road a year, waste 10 minutes of their life after reducing the speed by 20% then the accumulative lose of time is 100 million minutes. This equates to 3 life times opportunity cost lost (at the average lifespan) that the lower speed limits ‘loses’ and is an unseen safer road, hidden road toll.
Ie for the above road you could have a higher speed limit and have 3 road toll deaths per year and still come out with savings in lifetimes over lower speed limits.
You don’t cares about millions of 10 minutes but everyone notices a fatal death. But they are equally important.
The opportunity cost of safety is sometimes more than the benefit saved. And we all make those calculations on a micro level every time we chose to drive.
I say the community can make their own decisions, not the govt in regards what is safe and acceptable risk. And the community has spoken.
Feel free to drive at the old ‘safer’ speed limits - there’s nothing stopping you. My grandma does it all the time
If you are really worried about safety, ban push bikes - they have the highest death rate per km travelled.