There are two of these types of memorials of car accident victims very near my home (one on the street to my subdivision). They have both been very well-maintained for years. There are several others around town too. Some people are spending a lot of energy to decorate street light poles and makeshift crosses.
I have mixed feelings about those. sometimes I think they are odd. I don't think I'd want someone maintaining the site of my fatal car accident. But then I read something like this:
http://www.kmtv.com/Global/story.asp?s=7345106
and I realize that some families really need these memorials. (I live in Omaha. Amber Harris went to the school in my neighborhood.)
I can see where Lee, in a fit of anger over his grief, just wanted to be able to come and go to the house without having this tragedy rubbed in his face even more. He has to be grieving over his niece (and his crazy sister's involvment) and seeing the cross might have just sent him over the edge a bit.