[parineum]

> They have breathalyzers and blood tests. Field sobriety tests are not there to help police arrest drunk drivers, they're there to help police arrest whomever they want to.

You're wrong about that. "Sobriety" isn't limited to alcohol. You'll notice that most laws against drunk driving are actually against being "intoxicated" or "impaired". Breathalyzers and blood tests are for gathering indisputable evidence.

Field sobriety tests are there to determine if you're motor skills are impaired. If an officer observers a person driving erratically and they can't walk a straight line or touch their own nose, they shouldn't be driving. You can be arrested for DUI [of sleeping pills].

The only time police would specify a DUI was for alcohol is if a breathalyzer or blood test showed that. Even if the officer says there was a beer can on the floor and they smelled like alcohol, they could be under the legal limit and be on any number of other substances so the DUI wouldn't specify alcohol.

[kube-system]

> If an officer observers a person driving erratically and they can't walk a straight line or touch their own nose, they shouldn't be driving.

There are plenty of reasons that someone might not be able to demonstrate this to the subjective opinion of an officer and be completely unimpaired and competent at driving. e.g. people with atypical minds or bodies

Police generally ask people to do these tests when they have already made up their mind about someone being impaired. The only point of the test, practically, is generate standardized documentation. It is a dog and pony show.

Other countries that have serious anti-driving-impairment programs don't use these types of subjective tests -- they test people for using the substances directly.

[parineum]

They'll have an opportunity to prove that in court. I know that's not a great solution (because of the penalties involved in simply being accused of a crime, but that's a different issue) but, remember, they were pulled over for driving erratically and the, through conversation, the officer would gain further reason to ask them to do the test. The problem is the driving, everything after that is evidence gathering.

These days, so much of that will be recorded on video, from the dash cam to the body cam, it's usually cut and dry that the person accused is under the influence of something.

> people with atypical minds or bodies

This is a reasonable concern so I don't want to dismiss it but this isn't even close to the typical situation and, to emphasize, the reason for the stop is usually bad driving and the officer is looking for an explanation. Before a sobriety test is administered, there is already a cause for being pulled over. So people who can't pass a sobriety test because they have a physical or mental reason they can't only have that one piece of evidence against them removed.

I'm sure you can construct a hypothetical case where a person with a speech impairment, an inner ear deformaty and who's eyes shake when moving left and right gets arrested for DUI because they appear impaired but they weren't pulled over for those reasons.

[kube-system]

The problem is that low-quality evidence causes both type 1 and type 2 errors.

Not only does it cause significant problems for people who are unjustly jailed and charged for crimes they didn't commit -- but it also lets drunk drivers off the hook when the flimsy evidence fails to convict. These aren't hypotheticals, both are very common.

Police in the US simply need to be equipped with roadside chemical tests for substances. They exist, they just simply don't use them.

Here's is an example of what other countries do:

https://adf.org.au/insights/roadside-drug-testing/

> The officer takes a sample of your saliva by placing an absorbent collector in the mouth or on the tongue. The sample is then analysed at the roadside. If the test is positive, it must be confirmed by laboratory testing before charges can be laid.

Doesn't that sound like a better solution than: "The officer makes you stand on one leg and say the alphabet backwards, if they don't like they way you did it, you are charged with DUI"?

> I'm sure you can construct a hypothetical case where a person with a speech impairment, an inner ear deformaty and who's eyes shake when moving left and right gets arrested for DUI because they appear impaired but they weren't pulled over for those reasons.

The more common, and even more scary issue, is that sometimes people undergoing medical emergencies are arrested for DUI and sent to jail instead of a hospital. Which is again another situation that would be avoided entirely by roadside testing. This is such a common issue for diabetics that police normally do train to recognize the difference, but since they are not medical professionals and don't have adequate equipment, they still often confuse the two.

Watch this dashcam video: https://www.wsmv.com/2025/10/02/retired-deputy-arrested-dui-...

[parineum]

> Police in the US simply need to be equipped with roadside chemical tests for substances. They exist, they just simply don't use them.

I feel like you're not getting my point.

> Doesn't that sound like a better solution than: "The officer makes you stand on one leg and say the alphabet backwards, if they don't like they way you did it, you are charged with DUI"?

No, it doesn't. DUI isn't a law that lists a bunch of chemicals that are illegal to drive while using. The purpose of the tests is to prove you shouldn't be driving, not what drugs you're on.

You could be over-tired and get a DUI and I think that's justified.

[kube-system]

Are you sure about that? Maybe your locale is different, but the DUI/OVI statute in the part of the US where I live is for influence of "alcohol or drugs" specifically. And it absolutely does have a list of what qualifies... and that list basically includes all drugs and alcohol.

Part of the criminal element of DUI is someone's choice to alter their body intentionally. I don't think many would think it would justly apply to natural processes like sleepiness or medical emergencies. That's not to say there shouldn't be penalties for failure to operate a vehicle safely, but those situations are clearly very different than DUI.

[parineum]

What I said there was confusing. I was saying that _I_ was fine with an over-tired person being charged with a DUI as I feel it's just as dangerous and just as elective. It is not the law here. That was unclear, sorry.

The relevant section of the law here is:

(f) It is unlawful for a person who is under the influence of any drug to drive a vehicle.

> And it absolutely does have a list of what qualifies... and that list basically includes all drugs and alcohol.

Does it state that the list is the exhaustive list? I have a hard time believing that someone could be pulled over, obviously inebriated but get off because they were actually on some new synthetic marijuana that wasn't on that list.

[feoren]

> remember, they were pulled over for driving erratically

Maybe. Or they were pulled over for being black, or having tattoos, or being really hot, or because they criticized police brutality on social media, or because the officer needs to hit their arrest quota by the end of the month, or because they're driving an expensive car and the officer thinks they'll have lots of cash they can legally rob via civil asset forfeiture. We have far, far too many examples of all of these happening to say with any certainty that the police officer actually suspects anyone of an actual crime.

By the way, I have called in drivers who were badly impaired before. One kept driving up onto the curb, on the sidewalk and grass (next to a school!), then swerving back nearly into the oncoming lane, then stopping in the middle of the road, etc. Another kept swerving toward the concrete barriers on the highway, and when I passed them, they looked visibly asleep. Both times, the cops didn't care. They didn't send anyone. They sounded annoyed that I was bothering about that crap. The police do not care whether people are driving drunk or not, just like they do not care whether an active shooter is gunning down kids in an elementary school. They don't care if a violent dad with a restraining order has kidnapped his kids and is about to murder them, even when the mom tells them exactly where he has taken them. Their interests are orthogonal to the just enforcement of the law.

[wredcoll]

> but they weren't pulled over for those reasons.

Yeah, good point, they were probably pulled over for being black.