>>>I don't know for sure but I think they say that testing a driver for DUI of pot is not easy or maybe not yet developed. That is, again, if I understand correctly, all current DUI testing methods are not detecting pot. Although you can smell it easy.
>>>I am not a pot smoker so I would not know.
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>>Actually pot in blood or urine is too easy to detect... weeks after the fact. I know of a person who got a job in a different state, relocation costs paid etc, but couldn't get employed because she was positive on pot test (and pot is legal in her home state). She didn't touch it for three weeks, and still tested positive.
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>What I meant is testing a driver with a breathalyzer, which is what cops use. I am sure that in hospitals or using blood tests, they can detect anything.

Over here swipe tests are used for THC, Meth, Opioids and Cocaine. Coupled with some expirience in movement watching this can be sufficient indicator to send people to blood tests (which are needed in all intoxication matters) similar to breathalyzer results for alcohol.

THC has less linear correlation of duration since ingestion and ability to drive. IMO the "surprise" effect should be catered for by very low thresholds allowable under DUI aspects. Opioid results can be misleading, as poppy on bread can screw some results depeding on metabolism, amount consumed and time since ingestion, which IS allowed.