I've had a drink, when can I drive again ?
Discussion
Derek Smith said:
I've been part of a test regarding how much one can drink before being over the limit and how quickly the level drops. This on a course to be an instructor for the stations based machine. I eventually became my force representative for drink drive law and practice. I visited the place where the machines (used to be) were manufactured in LLantrisant.
The numbers taking part were not statistically significant, just 8, but this had been done many times before and the results were consistent.
The MO was for people to drink alcohol and then be tested after a set period.
There were nine of us, but as I was tee-total I ended up testing everyone on the substantive breath test machine, the one used in the police station.
The undeniable conclusion, not only from our lot but from all courses, is that there is no consistency.
There are general pointers - rules is too strong a word.
Women peak higher for the same quantity of alcohol, stay high for longer and take longer to drop.
The bigger the person, the slower the rise in score.
If a person rises slower, they will peak lower.
Not apparent in our group, but if a person is ill, such as a cold, all bets are off.
A full meal slows the intake of alcohol and lowers the total score, but there is a big however. See later.
A person with lower body fat will peak higher, sooner and drop quicker. If the person is very fit then they are even more so (and serve them right).
The variation on all measurements is remarkable. So the main rule is that there are no rules.
One person who did not eat but drank two double shorts then went onto beers did not blow positive during the test, that's about four hours from the first drink. However, some 14 hours after the first drink, he blew just over. The explanation was that the neat alcohol made the sphincter muscle at the bottom on his stomach and made it contract stopping the alcohol going into the intestines.
Also there are variations in readings taken closely. So the increase in the reading is not linear. Nor is the drop.
As I said, those who ran the course said that our experiences were the norm. They occasionally got exceptional readings: very high/very low. No explanation was known for these aberrations.
The conclusion of those who ran the course, supported 100% by our experiment, is that there are no consistencies that can be depended on.
There were other observations about inebriation, but that's a different subject.
Great post, as a scientist I appreciate the straight-to-the-point findings.The numbers taking part were not statistically significant, just 8, but this had been done many times before and the results were consistent.
The MO was for people to drink alcohol and then be tested after a set period.
There were nine of us, but as I was tee-total I ended up testing everyone on the substantive breath test machine, the one used in the police station.
The undeniable conclusion, not only from our lot but from all courses, is that there is no consistency.
There are general pointers - rules is too strong a word.
Women peak higher for the same quantity of alcohol, stay high for longer and take longer to drop.
The bigger the person, the slower the rise in score.
If a person rises slower, they will peak lower.
Not apparent in our group, but if a person is ill, such as a cold, all bets are off.
A full meal slows the intake of alcohol and lowers the total score, but there is a big however. See later.
A person with lower body fat will peak higher, sooner and drop quicker. If the person is very fit then they are even more so (and serve them right).
The variation on all measurements is remarkable. So the main rule is that there are no rules.
One person who did not eat but drank two double shorts then went onto beers did not blow positive during the test, that's about four hours from the first drink. However, some 14 hours after the first drink, he blew just over. The explanation was that the neat alcohol made the sphincter muscle at the bottom on his stomach and made it contract stopping the alcohol going into the intestines.
Also there are variations in readings taken closely. So the increase in the reading is not linear. Nor is the drop.
As I said, those who ran the course said that our experiences were the norm. They occasionally got exceptional readings: very high/very low. No explanation was known for these aberrations.
The conclusion of those who ran the course, supported 100% by our experiment, is that there are no consistencies that can be depended on.
There were other observations about inebriation, but that's a different subject.
What has been missed, buried deep in there is the highlighted little gem....
A couple of double shorts on an empty stomach before an evening session, a puckered-up intestinal sphincter, 4 pints of ale over the next 4 hours, then blow negative on the way home. Jobs a goodun.
Obviously wouldn't recommend it, but it shows that there could be flaws to the system.
oilydan said:
Great post, as a scientist I appreciate the straight-to-the-point findings.
What has been missed, buried deep in there is the highlighted little gem....
A couple of double shorts on an empty stomach before an evening session, a puckered-up intestinal sphincter, 4 pints of ale over the next 4 hours, then blow negative on the way home. Jobs a goodun.
Obviously wouldn't recommend it, but it shows that there could be flaws to the system.
Thanks for that.What has been missed, buried deep in there is the highlighted little gem....
A couple of double shorts on an empty stomach before an evening session, a puckered-up intestinal sphincter, 4 pints of ale over the next 4 hours, then blow negative on the way home. Jobs a goodun.
Obviously wouldn't recommend it, but it shows that there could be flaws to the system.
The following morning everyone was put on the machine and most gave a reading, none over apart from this lad, who was in a dreadful state. When it was explained to him that the sphincter at the beginning of his intestines had contracted or gone into spasm, he said it was a shame that the one at the other end had not.
One thing which came out from our test: everyone was asked when they would believe they were too unfit to drive. All but two put it at less than half of the prescribed limit. The chap who blew negative didn't get anywhere near half until late in the evening and by that time it had become raucous and the question was not put. The other one was a front row forward, although he'd slimmed down a bit since stopping playing. He said he felt fine at the half-way point. However, he said he'd have put the car keys away a little later, perhaps a pint, while still blowing under. To me he seemed fine. If memory serves, he blew the second highest the following day.
The woman in our group, unused to drinking, was the highest scorer that evening despite having one of the lowest intakes of alcohol. She still registered the following morning.
We had one chap whose hobby was running. Marathons, which was unusual in those days. He held some police record for the fastest over a certain distance - memory fades as to which one, but I can't believe there were enough police officers willing, nor indeed able, to run marathons in those days to make a race. He spent his life planning his menu and weighed a bit less than my foot. That said, I wear 11s, but a 12 fits.
He peaked early, and was over the limit after three pints, and the conclusion was that he would probably have been over at 2 pints. He was below the limit within half an hour, despite drinking about a quarter of a pint of beer. But only just under. He then went off to drink water, came back but felt too ill to stay the distance.
That'll teach him to be so fit.
That said, I used to cycle everywhere in those days, 200+ miles a week, mainly off road on the Downs, and was the fittest I'd ever been. I blew in the machine and it objected. It had a filter which switched the machine off if it detected keytone(?) in the breath, which can be a symptom of diabetes. I was later told by my doctor that I was 'fine. Just a bit too fit.'
Don't get doctors like that anymore.
Edited by Derek Smith on Wednesday 10th December 20:16
Interesting. Thanks Derek - always worth reading your posts.
http://en.wikipedia.org/wiki/Ketosis
Derek Smith said:
it detected keytone(?) in the breath
For reference:http://en.wikipedia.org/wiki/Ketosis
SamHH said:
Nigel Worc's said:
I'm absolutely in agreement with you regarding Scotland, and I'm struggling to believe that what they are proposing to do is actually legal.
What are they proposing to do and why is it illegal?Nigel Worc's said:
They are proposing to ban people from driving on English & Welsh roads for failing a Scottish limit test.
Not quite. They're banning people from driving on UK roads for failing a UK breath test.Oh, and they're not "proposing" anything, the changes have already happened.
Nigel Worc's said:
They are proposing to ban people from driving on English & Welsh roads for failing a Scottish limit test.
Why do you think that is illegal?What distinguishes the situation you just described from any situation where a person loses a privilege in one jurisdiction for having committed an offence in another jurisdiction?
hora said:
Nigel Worc's said:
Roughly 12 hours from my last drink is good enough for me chaps, I don't do it very often, hence the question, I wouldn't drive if I felt impaired anyway, alcohol related or not.
As long as I feel ok, legal is what I'm looking for, rather than zero.
I thought it was from when you started as alcohol is gradually being taken/processed? So - if you partake in 12 units from say 7pm to 11pm. You'd be processing a unit from 7pm onwards - 4 units actively cleared within 7-11pm sesh then all clear from system by 7am depending on liver impairement/efficiency? As long as I feel ok, legal is what I'm looking for, rather than zero.
Drinking 4 units will take a male to about 60mg i.e legal. This is two pints of med 4% lager. You could drink 1 pint ever two hours and stay legal. 4 pints in 4 hours
JonRB said:
Interesting. Thanks Derek - always worth reading your posts.
http://en.wikipedia.org/wiki/Ketosis
Thanks for the comment and the link as well.Derek Smith said:
it detected keytone(?) in the breath
For reference:http://en.wikipedia.org/wiki/Ketosis
I used to cycle the 18 miles to work as fast as I could. Most of it was on bridleways and I went up and down the Downs. I would get to work, shower, run to my office and then start work, in this case teaching traffic law and practice, buzzing. Not a good idea with traffic officers.
I came in one morning to teach something about the breath test machine at the station. As part of the initial demonstration I blew into the device only for it to stop. Out came the book with the instruction to see a doctor and take a urine sample.
He told me to ease up of a morning but didn't say why. I asked our force surgeon if it was something to worry about, but if it didn't respond to paracetomol or having a plaster put on it, he was at a loss. For a while after that I'd occasionally take a BT to test my levels. I found that if I had had a 'good' ride in, i.e. really pushed it, then I could sod about with the machine. However, it only lasted a few minutes. If I waited half an hour, it was normal.
The link explains it, certainly better than the force surgeon ever could. It makes me wonder at what level the keytone sensor was set at.
Derek Smith said:
Thanks for the comment and the link as well.
I used to cycle the 18 miles to work as fast as I could. Most of it was on bridleways and I went up and down the Downs. I would get to work, shower, run to my office and then start work, in this case teaching traffic law and practice, buzzing. Not a good idea with traffic officers.
I came in one morning to teach something about the breath test machine at the station. As part of the initial demonstration I blew into the device only for it to stop. Out came the book with the instruction to see a doctor and take a urine sample.
He told me to ease up of a morning but didn't say why. I asked our force surgeon if it was something to worry about, but if it didn't respond to paracetomol or having a plaster put on it, he was at a loss. For a while after that I'd occasionally take a BT to test my levels. I found that if I had had a 'good' ride in, i.e. really pushed it, then I could sod about with the machine. However, it only lasted a few minutes. If I waited half an hour, it was normal.
The link explains it, certainly better than the force surgeon ever could. It makes me wonder at what level the keytone sensor was set at.
Out of curiosity did you eat prior to your journey or after it at all?I used to cycle the 18 miles to work as fast as I could. Most of it was on bridleways and I went up and down the Downs. I would get to work, shower, run to my office and then start work, in this case teaching traffic law and practice, buzzing. Not a good idea with traffic officers.
I came in one morning to teach something about the breath test machine at the station. As part of the initial demonstration I blew into the device only for it to stop. Out came the book with the instruction to see a doctor and take a urine sample.
He told me to ease up of a morning but didn't say why. I asked our force surgeon if it was something to worry about, but if it didn't respond to paracetomol or having a plaster put on it, he was at a loss. For a while after that I'd occasionally take a BT to test my levels. I found that if I had had a 'good' ride in, i.e. really pushed it, then I could sod about with the machine. However, it only lasted a few minutes. If I waited half an hour, it was normal.
The link explains it, certainly better than the force surgeon ever could. It makes me wonder at what level the keytone sensor was set at.
Foliage said:
Out of curiosity did you eat prior to your journey or after it at all?
I tended to have a light breakfast, just a slice of bread/toast, although if the latter I indulged in copious blobs of butter. I used to drink a couple of litres of water before/during the ride.Following advice from my doctor I ate cereal but this made me burp en route. I used to take a couple of bananas with the avowed intention of eating whilst cycling but hardly ever got around to it.
It didn't seem that much of a problem. I was a bit on the light side but not excessively so. I felt good - I felt great in fact - so just carried on as before in the main.
By mid-morning I was hungry and during a short coffee break I'd eat sarnies that I took with me. Then at lunch I'd stuff my face. I'd eat a lightish dinner.
My level of Ketone (ta) was felt not to be excessive although I was told to have it checked regularly, which I did using the machine. It rarely showed positive unless I blew as I got off the bike. The main problem was low blood pressure, which I had to have checked every fortnight at one time until I discovered that (in those days?) it was all but untreatable. When I challenged this with my doctor I was told to come back when I had collapsed.
On the return trip I would take it a little easier in the main, although the climb over the Downs was very steep at one point, to the extent that the bike turned over backwards once. Instead of getting home all up tight after an irritating day or with terrible traffic, I would come in completely relaxed.
I was attacked by a sparrowhawk once, and another time have four punctures on the route home, but otherwise it was relaxing. I toyed with the idea of jogging to work in the morning and cycling back and doing the opposite the next time. Never got around to it. I enjoyed cycling so much.
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