The British government is using road safety as an excuse for draconian drug enforcement.

Quote: "As somebody who recently lost a very close friend to a driver who tested positive for methamphetamine, I support any means to deter drug impaired driving."
While I do sympathize, I don't count someone's personal loss as legitimate justification for general legislation.
And phrases like "I support any means" send up a red flag.
Just sayin'.
"Zero tolerance" policies in the U.S. have, with few if any exceptions, been dismal failures leading to widespread gross injustice. I know you wrote people need the information to make responsible decisions, and I agree. But at the same time, irresponsible legislation is irresponsible legislation.

You're not a real pothead until you start spouting about how healthful and non-addictive it is!

As with most limits it will be Monday morning commuters barely over the limit from Saturday night who are hit hardest.

What you do not want to encourage , is someone who in the past would wait a couple of days before driving after partaking, coming to the decision that with the tolerances set it makes no difference waiting and then drives whilst still under the influence with much more dangerous likely outcomes.

I think the big question is, has a driver been stopped because his driving appears to be erratic, or is it a random check? I.e., has the drug affected the driver's ability to drive?
I'm sure there are a lot of accidents caused by tiredness. I have come close to this myself. On the other hand I have never taken any sorts of drugs, except alcohol. I have had no convictions for drink driving.
I would be interested to know the number of drivers who have been convicted of driving under the influence of drugs and causing an accident.
This article is the first I have heard of this new legislation, and I live in England.

We have an election coming up, so to hell with people's livelyhoods, let's show just how tough we can be. At this point all the blue rinse brigade will be sagely nodding their heads, they way they did when it was announced that young offenders would be given short sharp shock treatment. Result a whole new generation of criminals sent on 'apprenticeships' in gaols where they could learn how to burgle, steal cars and rob properly. Duh!
Of course there should be limits to drink and drug driving, but not ones where a person can lose their licence for something they did days ago and is no longer affecting their driving. That is just plain daft. I suppose when enough people have lost their licences and enough of their favourite bankers, who, incidentally, are allowed to get away with laundering drug money, have had to lean on their mates in the police and government to get their charges dropped, they will quietly alter the limits to something more realistic.
As for legislating to make cars more drug and alcohol friendly, that would be asking too much, wouldn't it? I mean, people might actually enjoy life a little, mightn't they? It would improve the economy by enticing people to go out for a meal or to see a show, so we can't have that. Can't expect politicians to realise that there is a load of technology that could be applied today to make cars much safer and save a lot more lives than this legislation ever will.
The main trouble is that most politicians are scientifically and technically illiterate. However, ask them about Plato and Socrates etc. and they will bend your ear on the subject, though it will be as irrelevant to today as it ever was.

Anyone who has visited the UK in the last 20 years has likely encountered a drunken lout engaged in public projectile vomiting "PPV". It is disgusting and very British. Seems the pubs keep on serving until their patrons puke. Nice? No! While every country has it's drunk drivers I suspect that the UK with it's history of drinking to a stupor after work every day may be relatively unique, Russia excepted. If they also do drugs with the same regularity then that is a problem. These laws are not draconian, it is easy to avoid prosecution, don't drink or do drugs and drive...duh!
If I were king, I'd also seize their cars and sell them at auction.

Once (upon a time) there was a factory worker who was given a machine to use at work which he promptly refused to use. When asked why by his line manager he said "Well, it's difficult to get going, it leaks oil, the electrics don't work properly, you have to keep topping up the coolant, the safety guards aren't working properly, not all the panel lights work and frankly it's dangerous"
The line manager looked at him and said "Bit like your car then, but you drive that POS to work every morning and don't seem to be worried about that?"
Moral of this story is - problem goes far, far deeper than potheads and drinkers. We need zero tolerance for people who drive death traps far more than this political spin

"But as a realist, I think it’s important to give recreational drug users the information they need to act responsibly."
Really? Aren't they already acting irresponsibly by taking illegal/legal drug for recreation? So why would we think for a moment they will act responsibly with information on how long they should wait until they can drive again when they are already breaking the law?
Here's a way to act responsibly, don't do drugs for recreational purposes. If you can't do that then do the next best thing, sell your car so you can have bus/cab/train fare to and fro.
By the way ... I also lost someone due to a driver under the influence.