Service Provision Areas, let's hunt me some homeless...

So they've got tracking homeless down to an equation. Through Service Provision Areas (SPA), the department of statistics of UCLA found that in the County of Los Angeles tracked that there were 64,000 homeless people in 2005.
I have to throw drug use into the mix also for the homeless population. There are a ton of studies so now I need to start narrowing it down from them.



Back to Glory holes(ps that link is pornographic), I've started mapping what I could. Here are some places, feel free to augment. Most of the glory holes that I have been mapping so far have been gay ones, the link I found has led me to interacial heterosexual glory hole-ing.