Whilst it won't be on my railroad I do think that the true graffiti has a place in society. By true graffiti I don't mean the mindless tagging and destruction of preprty, but artists doing work in allowed area's.
In Leicester, UK, a few years a go a huge fence was put up a round a redevelopment site. Knowing it was going to get covered in graffiti anyway they held a competition. Some of the 'Artists' simply did tagging which spoilt the effect somewhat, but some of the fence panels were stunning works of art.
They have a novel approach in one of the villages I know in Holland as well. They have a Graffiti wall. Every so often it's painted over and the kids start again. Some of that is very good as well, and the village doesn't seem to have the graffiti problem that the rest of the Netherlands seems to have to endure - theproblem over here is 10 times worse than the parts of the UK I have seen, including peoples houses.
Just my t'penny worth
Stu