But its a stupid idea in the first place.
This train of thought is exactly like the train of thought behind the HiViz debate for motorcyclists "it will work because we say it works, we'll just ignore the fact preteens are already smoking and everyone turns a blind eye."
Id prefer the far less lethal form to freely available over the counter instead of some moron shooting up something cut with petroleum.
What you (and a few others) need to realise is most drugs are naturally occurring products and the adverse side affects caused by some are from synthed or...
No experience in it, but I dont know many areas here that would accommodate any real speeds.
You could try mountainboarding, you can use the DH tracks at most ski resorts during the warmer seasons.