Legal limit of what, speed limit? I have never drank and drove on public roads, private yes, I would fully admit that, but never intoxicated past a legal limit. Lost friends and a fiance to drunk drivers it's not about indiscriminately, it's about consequences for your choices and who they effect.
Don't get me wrong, I'm not "pro drunk driving." After a second offense it's very difficult to get your license back and after a 3rd it's almost impossible. However,I'd like you to consider something with an open mind. A person I worked with who claimed he wasn't a pot smoker(we live in PA) said he got a DUI simply because he had Marijuana in his system. Their is no "legal limit" on Marijuana because it is a federally controlled substance. Because of US "mandatory minimums," he lost his CDL. As he told me, his roommate smokes Marijuana, but he does not. After seeing the levels in in his case, I'm inclined to agree with him. But I don't think people in the US fully understand this, you can get a DUI simply for driving without enough sleep.
So where I'm going with this is, if you're driving with too little sleep, can your car stop you from driving? I have epilepsy and what I take for it are depressants. Should my car stop driving because the drugs I take to prevent seizures look to the car's AI as I'm driving under the influence?
Driving under the influence is wrong, I won't dispute that at all. What I will dispute is that cars shouldn't be the ones making the decision if your intoxicated or not.