Cannabis & Driving
Discussion
My 17 year old son has just started driving (test booked but not taken yet) and I'm currently letting him drive everywhere for practice.
I know that when he is out with his mates at the weekend, there is a chance he might smoke cannabis and I have heard horror stories of people being over the limit and banned for drug driving on a Wednesday after smoking a joint on the Saturday. There seems to be all sorts of various information that seems to suggest anywhere between 24 hours and a week as a safe amount of time before driving.
Just wondered if anyone was willing to share any real world experience of this?
I know that when he is out with his mates at the weekend, there is a chance he might smoke cannabis and I have heard horror stories of people being over the limit and banned for drug driving on a Wednesday after smoking a joint on the Saturday. There seems to be all sorts of various information that seems to suggest anywhere between 24 hours and a week as a safe amount of time before driving.
Just wondered if anyone was willing to share any real world experience of this?
cashmax said:
My 17 year old son has just started driving (test booked but not taken yet) and I'm currently letting him drive everywhere for practice.
I know that when he is out with his mates at the weekend, there is a chance he might smoke cannabis and I have heard horror stories of people being over the limit and banned for drug driving on a Wednesday after smoking a joint on the Saturday. There seems to be all sorts of various information that seems to suggest anywhere between 24 hours and a week as a safe amount of time before driving.
Just wondered if anyone was willing to share any real world experience of this?
Two offences when it comes to drug driving. I know that when he is out with his mates at the weekend, there is a chance he might smoke cannabis and I have heard horror stories of people being over the limit and banned for drug driving on a Wednesday after smoking a joint on the Saturday. There seems to be all sorts of various information that seems to suggest anywhere between 24 hours and a week as a safe amount of time before driving.
Just wondered if anyone was willing to share any real world experience of this?
Driving whilst unfit through drugs. Think off their head. All over the road etc.
Driving whilst over the specified limit. Similar to alcohol there is a legal limit. For cannabis its 2.0. No idea in what units. And of course there is no way to messure how much one spliff would be as it depends on how much is in there, how strong it is etc. It also varies on how quickly it leaves the system.
I've drug wipped people who said they used it the day before and it was negative. I've had people say they smoked it two weeks ago and it was positive.
If its positive its arrested, trip to custody for a blood sample and then a waiting game. Blood results are taking months to come back (five-ish at the moment). If over the limit its a 12 month ban for the first offence minium.
I arrest more people for over the specified limit than unfit.
My advice is to make a decision. If he wants his driving licence, don't take the risk by smoking cannabis. I've had a few collisions were someone was involved in a fatal and tested positive for cannabis. They've now lost their licence.
Don't want to be overly judgemental towards the OP, he's not suggesting he should allow his son to drive high, he's asking when it is definitively safe for him to drive should he smoke a spliff or two at the weekend.
I suspect the numbers are all over the place as there is no legal limit for cannabis as there is for alcohol - so technically any trace found in his blood should he be involved in an incident would probably be enough for a drug driving charge. This could mean that well after any noticeable effects have worn off, there could still be a detectable amount of active substance sloshing around which could get him in trouble.
Conversely, because there's no legal position on it, there's no easily quantifiable data either. How strong is the stuff he's smoking? How much did he put in the joint? etc, etc.
Easy solution is zero tolerance on your part I would say. Any suspicion of smoking at the weekend, no driving that week. Or, even better, no driving at all until he learns you have to make sacrifices to be safe.
Once he has his own car and licence, regrettably he'll be able to do what he wants.
I suspect the numbers are all over the place as there is no legal limit for cannabis as there is for alcohol - so technically any trace found in his blood should he be involved in an incident would probably be enough for a drug driving charge. This could mean that well after any noticeable effects have worn off, there could still be a detectable amount of active substance sloshing around which could get him in trouble.
Conversely, because there's no legal position on it, there's no easily quantifiable data either. How strong is the stuff he's smoking? How much did he put in the joint? etc, etc.
Easy solution is zero tolerance on your part I would say. Any suspicion of smoking at the weekend, no driving that week. Or, even better, no driving at all until he learns you have to make sacrifices to be safe.
Once he has his own car and licence, regrettably he'll be able to do what he wants.
LosingGrip said:
Two offences when it comes to drug driving.
Driving whilst unfit through drugs. Think off their head. All over the road etc.
Driving whilst over the specified limit. Similar to alcohol there is a legal limit. For cannabis its 2.0. No idea in what units. And of course there is no way to messure how much one spliff would be as it depends on how much is in there, how strong it is etc. It also varies on how quickly it leaves the system.
I've drug wipped people who said they used it the day before and it was negative. I've had people say they smoked it two weeks ago and it was positive.
If its positive its arrested, trip to custody for a blood sample and then a waiting game. Blood results are taking months to come back (five-ish at the moment). If over the limit its a 12 month ban for the first offence minium.
I arrest more people for over the specified limit than unfit.
My advice is to make a decision. If he wants his driving licence, don't take the risk by smoking cannabis. I've had a few collisions were someone was involved in a fatal and tested positive for cannabis. They've now lost their licence.
The correct procedure is arrest for unfit then charge with OPL. Police often get this wrong and the charge is amended at court.Driving whilst unfit through drugs. Think off their head. All over the road etc.
Driving whilst over the specified limit. Similar to alcohol there is a legal limit. For cannabis its 2.0. No idea in what units. And of course there is no way to messure how much one spliff would be as it depends on how much is in there, how strong it is etc. It also varies on how quickly it leaves the system.
I've drug wipped people who said they used it the day before and it was negative. I've had people say they smoked it two weeks ago and it was positive.
If its positive its arrested, trip to custody for a blood sample and then a waiting game. Blood results are taking months to come back (five-ish at the moment). If over the limit its a 12 month ban for the first offence minium.
I arrest more people for over the specified limit than unfit.
My advice is to make a decision. If he wants his driving licence, don't take the risk by smoking cannabis. I've had a few collisions were someone was involved in a fatal and tested positive for cannabis. They've now lost their licence.
A lot of people in their Ivory Towers on this subject.
AFAIK cannabis can stay in your system for up to 21 days. I don't know if how regularly or much you smoke has any baring on this. I'd imagine that's where the limits to gauge come in. Had a smoke at the weekend, driving on Weds, under said limit. Been round mates, sharing a bong, drive home afterwards, over. Just my guess.
I'd suggest being over the limit days later would be really unfair. I have very sporadically smoked weed, and whilst there is no way I'd drive the same evening, the day or days after I would see no problem.
AFAIK cannabis can stay in your system for up to 21 days. I don't know if how regularly or much you smoke has any baring on this. I'd imagine that's where the limits to gauge come in. Had a smoke at the weekend, driving on Weds, under said limit. Been round mates, sharing a bong, drive home afterwards, over. Just my guess.
I'd suggest being over the limit days later would be really unfair. I have very sporadically smoked weed, and whilst there is no way I'd drive the same evening, the day or days after I would see no problem.
Too big a risk imo.
An amusing thread about this subject below.
https://www.pistonheads.com/gassing/topic.asp?h=0&...
An amusing thread about this subject below.
https://www.pistonheads.com/gassing/topic.asp?h=0&...
My understanding is that when the limits were set the expert recommendation was 10.0.(ppm/litre?), broadly in-line with other European countries. However it was decided a ‘zero-tolerance’ limit of 2.0 would send a message. Information on time-limits until safe is understandably scarce due to difficulty in studying a prohibited substance but from what I can gather an occasional smoker with low tolerance (therefore light use) will generally pass a road-side test within 24hours whilst a regular, heavy smoker has a permanent background level that can take weeks to clear. But neither party would necessarily be cognitively impaired anymore than you would the day after a heavy drink.
Basically best to think about it as really draconian drink-drive limit. Essentiallly zero-tolerance.
As for the OP’s son…you just need to impress upon him that if he smokes (and he probably will at some point) no driving for couple of days. Just like you’d tell them not to drink-drive. Not worth the risk.
Basically best to think about it as really draconian drink-drive limit. Essentiallly zero-tolerance.
As for the OP’s son…you just need to impress upon him that if he smokes (and he probably will at some point) no driving for couple of days. Just like you’d tell them not to drink-drive. Not worth the risk.
DaiB said:
Don't want to be overly judgemental towards the OP, he's not suggesting he should allow his son to drive high, he's asking when it is definitively safe for him to drive should he smoke a spliff or two at the weekend.
I suspect the numbers are all over the place as there is no legal limit for cannabis as there is for alcohol - so technically any trace found in his blood should he be involved in an incident would probably be enough for a drug driving charge. This could mean that well after any noticeable effects have worn off, there could still be a detectable amount of active substance sloshing around which could get him in trouble.
Conversely, because there's no legal position on it, there's no easily quantifiable data either. How strong is the stuff he's smoking? How much did he put in the joint? etc, etc.
Easy solution is zero tolerance on your part I would say. Any suspicion of smoking at the weekend, no driving that week. Or, even better, no driving at all until he learns you have to make sacrifices to be safe.
Once he has his own car and licence, regrettably he'll be able to do what he wants.
Yes there is. Have a look at Section 5A Road Traffic Act.I suspect the numbers are all over the place as there is no legal limit for cannabis as there is for alcohol - so technically any trace found in his blood should he be involved in an incident would probably be enough for a drug driving charge. This could mean that well after any noticeable effects have worn off, there could still be a detectable amount of active substance sloshing around which could get him in trouble.
Conversely, because there's no legal position on it, there's no easily quantifiable data either. How strong is the stuff he's smoking? How much did he put in the joint? etc, etc.
Easy solution is zero tolerance on your part I would say. Any suspicion of smoking at the weekend, no driving that week. Or, even better, no driving at all until he learns you have to make sacrifices to be safe.
Once he has his own car and licence, regrettably he'll be able to do what he wants.
agtlaw said:
The correct procedure is arrest for unfit then charge with OPL. Police often get this wrong and the charge is amended at court.
Out of interest, why is this? I don't arrest for unfit unless there is evidence of someone being unfit (poor driving, poor results on a Field Impairment Test for example). I'll only arrest for OSL limit if there has been a positive drug wipe. If I've arrested someone for unfit, when going through the MGDD/B I'll always say that they are under investigation for unfit and OSL.
LosingGrip said:
Out of interest, why is this? I don't arrest for unfit unless there is evidence of someone being unfit (poor driving, poor results on a Field Impairment Test for example). I'll only arrest for OSL limit if there has been a positive drug wipe.
If I've arrested someone for unfit, when going through the MGDD/B I'll always say that they are under investigation for unfit and OSL.
The bar for unfit is lower. The driver can be unfit to drive through drink or drugs but below the statutory limit. You can arrest for unfit without doing a preliminary test; s.4(6)If I've arrested someone for unfit, when going through the MGDD/B I'll always say that they are under investigation for unfit and OSL.
Arrest for OPL is after preliminary test or failure to provide; see 6D
DaiB said:
Don't want to be overly judgemental towards the OP, he's not suggesting he should allow his son to drive high, he's asking when it is definitively safe for him to drive should he smoke a spliff or two at the weekend.
I suspect the numbers are all over the place as there is no legal limit for cannabis as there is for alcohol - so technically any trace found in his blood should he be involved in an incident would probably be enough for a drug driving charge. This could mean that well after any noticeable effects have worn off, there could still be a detectable amount of active substance sloshing around which could get him in trouble.
Conversely, because there's no legal position on it, there's no easily quantifiable data either. How strong is the stuff he's smoking? How much did he put in the joint? etc, etc.
Easy solution is zero tolerance on your part I would say. Any suspicion of smoking at the weekend, no driving that week. Or, even better, no driving at all until he learns you have to make sacrifices to be safe.
Once he has his own car and licence, regrettably he'll be able to do what he wants.
Completely wrong. I suspect the numbers are all over the place as there is no legal limit for cannabis as there is for alcohol - so technically any trace found in his blood should he be involved in an incident would probably be enough for a drug driving charge. This could mean that well after any noticeable effects have worn off, there could still be a detectable amount of active substance sloshing around which could get him in trouble.
Conversely, because there's no legal position on it, there's no easily quantifiable data either. How strong is the stuff he's smoking? How much did he put in the joint? etc, etc.
Easy solution is zero tolerance on your part I would say. Any suspicion of smoking at the weekend, no driving that week. Or, even better, no driving at all until he learns you have to make sacrifices to be safe.
Once he has his own car and licence, regrettably he'll be able to do what he wants.
Various drug driving limits have been in force since 2015.
In 2023, drug driving prosecutions exceed drink driving prosecutions.
https://www.gov.uk/government/collections/drug-dri...
What often happens in practice, and how people often get caught, when a driver is impaired through drunk or drugs:
They know they’re near or over the limit, so, after making the decision to drive, they take care. Or so they think. They stay under the limit, don’t run red lights etc. but that takes a lot of their concentration, too much. And they just don’t see the other car, or the pedestrian, or the careless biker.
All drivers who chose to break the law with drink, drugs, speeding, dodgy tyres etc are relying on every other road user behaving impeccably, and as we all know, that’s NEVER the case.
Buy him a suitcase and tell him that if he is ever caught driving under the influence, he can put his belongings in it and gtf out of your house.
They know they’re near or over the limit, so, after making the decision to drive, they take care. Or so they think. They stay under the limit, don’t run red lights etc. but that takes a lot of their concentration, too much. And they just don’t see the other car, or the pedestrian, or the careless biker.
All drivers who chose to break the law with drink, drugs, speeding, dodgy tyres etc are relying on every other road user behaving impeccably, and as we all know, that’s NEVER the case.
Buy him a suitcase and tell him that if he is ever caught driving under the influence, he can put his belongings in it and gtf out of your house.
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