Is there an available test? Can someone go to court and say “I pulled bingers yesterday so I was not high”? I seriously dont know.
No test that can be done out on the road that I know of. But in an office, yes. I’m not a lawyer and would guess that some level of suspicion would be needed. Maybe a failed field sobriety test? (re. “touch your nose...” etc.) or someone driving 15 mph in a 70 and babbling nonsense during a car stop? It’s been done, though, and much. CO’s been raking in some revenues.