https://www.oregonlive.com/politics/2015/07/marijuana_and_dr...
In other words, this isn't something that anyone who gets stopped goes through. You get tested if you're driving erratically.
Driving is a privilege. It's easy enough to avoid doing it while high.
Only insomuch as those techniques have nothing to do with alcohol specifically and can be applied to any situation, including sleepy drivers.
> In other words, this isn't something that anyone who gets stopped goes through. You get tested if you're driving erratically.
Not true. You could be pulled over for a variety of reasons, anything from speeding to a broken tail-light or just because the cop thinks you look like a stoner and is betting he'll be able to bust you. From the article you linked:
> The officer evaluates the driver. Some signs are obvious: bloodshot eyes, candy bar wrappers and what Iwai calls the "typical Beavis and Butthead laugh." Others are more subtle -- for example, slightly protruding veins on the person's neck.
So the officer makes some subjective judgements that will allow him to administer the test and whether it comes back positive or negative, we have not established that the driver was actually impaired and this is critical because the test would then allow the officer to imprison the citizen even if they were not driving erratically. The suggestion that you'll only be pulled over for driving erratically is not true.