I think it's a rule of horror movies that the characters can't learn the first time. It either comes back to bite them later in the movie or they do a sequel.
Or a combination of the two? Don't live right next to a freeway and build a large fence so your kids can play in the yard because let's be honest - drivers don't always pay that much more attention on residential streets either.
Probably a good policy. I don't know how much I believe that this stuff actually happened to that family because some of it is really hard to believe.