I second that. And a mostly deserted one, not a heavily used MUP.

Or quiet gravel roads.

From my days getting high (mostly long long ago), I think that the impairment to your judgement, motor skills, and safety are not as great as for alcohol, whether operating a bike or a motor vehicle, but just like driving drunk, I think that considering the risk to those around you is a far greater moral imperative than the personal risk.