My views wont be popular because we like to hear what we want to believe...
but i can tell you that with 16 years experience as a firefighter specialising in Road traffic accidents , i have attended some horrific accidents where the drivers have clearly been stoned. ( if you smoke yourself you can spot the signs )
Once youve seen a few innocent lives forever changed by someone who couldnt control their need to get high you soon change your mind.
If it was just you on the road then sure go for it but when you have to share the road with other drivers, cyclists , mothers with strollers etc in my view its beyond selfish.
There is no doubt that it reduces my sharpness and reactions you are changing the way your brain works when you get high. I failed 4 driving tests as a teenager because i was stoned. Took it the 5th time sober and passed.
I cant convince you other wise but just ask yourself if you may be deceiving yourself because you want to believe its safe. ...just like all the drink drivers that tell themselves they are fine to drive.
Ask yourself how you will live with yourself if you skipped just one of the hundreds of red light you come accross and smashed into, killing a young mother or had a single momentary lapse and didnt look to the side before pulling out crushing a child cycling to school. You would always ask yourself till the day you die if it was because you were stoned.
I have enough near misses when im not stoned !!
Just my thoughts
I hear what you and others are saying, but think most are talking about STONED, as in blitzed. Fully agree no one should drive in that state for their own sake and even more the sake of others.
But, it's easy to have a light relaxing buzz - especially with vapor and some of the excellent portables out now (VC & Mi, my personal favs). Just as I'll drive after a glass of wine (or maybe two depending on time spent & food) at dinner, I'll vape a small load or head out after vaping at home.
Does it impair my skills, attention or driving capabilities? I'm sure it does - even if just a little bit. Does it impair me any more than stress or being overly concerned about other things? I'd say usually not. About a month ago I stopped at a red light like it was a stop sign, then pulled off across the intersection. TOTALLY STUPID ASS and was very lucky no one was coming the other way during rush hour in a small city. But, I hadn't even vaped in more than 20 hours. I was worrying about some work bullshit and not paying attention. After I got done freaking out at myself for being such a total dumbass, I detoured to the less traveled path for the rest of my commute and casually took 3 hits from my Mi. Say what you will, but I would say I was a better driver and more attentive to my driving after those hits than before.
Also, let's be real here. There are plenty (MILLIONS!) of dumb MFs out here that shouldn't even have licenses because of how poorly they drive. The ones that are just aggressive or assholes could probably do with a few hits themselves to chill out and make them realize the minute or two they're going to get to their destination sooner aren't worth the risks, or being such a dick to others on the road. But most, who are just lost in their own world like they are the only ones on the road, are already driving way more spaced out and inattentively then I would ever be (even stoned), and are already way more dangerous than I'd be after smoking a whole joint or pushing 3-4 full loads through my vape.
I really got a kick out of the story about failing driver's tests stoned. Things were a bit different for me (tho some 30+ years ago). I had driver's ed in HS right after lunch. So, I was way more stoned for every session than I'd dare drive now. My driving partner (always 2 students & teacher) was a stoner, too. He and I were two of the biggest potheads in the school and would typically inhale at least 1/2 a joint each in our daily lunch group smokeouts with others - usually more than that. We also had no issues in our driving sessions. The one time I drove with another student - a goody two shoes type - she totaled a mailbox on a three point turn, and went the wrong way on a one way road (thankfully in a nearly barren mall parking lot). These were outside of a few times where the instructor had to hit his brake pedal (on the passenger side), which he never even reached for with my stoner friend or me. I was along during her regular time in the morning, so not stoned - and wishing I was!
So, does my light vaping on the road make me more like the girl who was so freaked at being behind the wheel she couldn't keep it together, or the idiots out here every day that are too caught up in their own little worlds to be good drivers? Yes, sure it does. Does it make me a worse, or less attentive driver than I would be without vaping? Sometimes yes, and sometimes no. But, does it relieve some of the stress of a rough work day, or brutal hour long each way commute? Hell yeah! Or, make those occasional several hour drives on the highway much more pleasant? Unquestionably!
Over the years I've had a few fender benders and a couple pretty bad accidents. Was not buzzed in the least in any, and all but one were not my fault (20 years ago tapped into someone from behind at 5 mph with bright sun in eyes and didn't see brake lights). I've also avoided many more with good reactions, both buzzed and not buzzed, as I'm sure everyone else does. Hell, that happens weekly if not more often.
I guess what I'm saying is it comes down to slightly less reaction times or attention while buzzed. I tend to pay a little more attention when buzzed because I know I am. But, even with that I'll admit that my brake foot may be a few milliseconds slower. IME milliseconds don't often come into play - a full second might - but I, and assume others, aren't losing that much reaction time. With all factors weighed, I'm probably better off with a few hits to chill, and others may be too. But, it's not for all and you have to be grown up and responsible about it. Some can do that, and others not so much.
DUI is DUI whether alcohol or weed. You're asking for trouble with the law, and putting yourself and others at risk - often fatal risk. But, that shouldn't take away from DWR (driving while relaxed) and keeping your attention and senses in the right direction. The only downside IMO is that I could get pulled over while actually vaping and be facing DUI charges, even though I'm nowhere near that. Those concerns only grow with THC swabs or other technologies that are being created. If I have a beer or two after work, and my BAC is below legal levels, I'll get a warning to be careful and be on my way. Breathalyzers and proper procedure should take care of all that. I fear the same will not be true with MJ detection during traffic stops, at least not for years as testing will probably be true/false; yes/no.
Be careful out there, safe and responsible. It's your responsibility as a driver for yourself and the rest of us out here on the roads. Watch out for LEO if you're doing anything remotely illegal. But, please get off of the high horse saying that I, or anyone else, is a danger to society (other drivers, people on bikes, mommys with strollers, etc) for taking a few vapor hits to chill out while trying to navigate the roads with all of the other idiots and assholes we all have to deal with every time we get behind the wheel.
.. like Groundhog Day 
