The streets are safer in your opinion in the scenario where 50% of pedestrians were killed?
I think you messed up your analysis somewhere. LOL
It’s not hard to understand.
The purpose was to show the effects that car over-reliance has on public safety and quality of life.
In the second scenario, everyone thinks the roads are too dangerous for kids (becuase they are, as evidenced by half of them getting killed) so they all drive their kids to school in oversized heavy vehicles making the roads even more dangerous.