In comparing it to alcohol, and I know that's difficult to do and I accept what you say, I guess that's the experience we have, so that's a natural comparison that we're making when thinking about this. People may know that while it may not be advisable, you could go out for dinner and have a glass of wine and drive home, and you're probably not over the legal limit. If you go out and have 10 glasses of wine and drive home, you're probably over the legal limit.
Is there a similar way to understand, while maybe not advisable, how much an individual can consume and be able to drive a motor vehicle without being impaired? Would there be a way to do that, similar to the one glass of wine? Can you smoke a little bit of weed and be able to drive under the legal per se limit thus proposed? How would a person know?