[dhaivatpandya]

Although the author may not have provided a citation for the claim, this has pretty much nothing to do with "life experience"? Roughly speaking, if you have a certain likelihood of knowing someone that dies in a car accident in a given year and every year of your life is somehow independent, it is not inconceivable that (most) people by the age of 50 know someone killed by a human-driven. car.

[nsgi]

Also, deaths in car accidents are decreasing, so older people are likely to have known more people that died in car accidents in their youth than younger people today.

[justincormack]

Depends on how many people you know and geographical distribution of accidents. It might be the case or it might not.