Drink Driving

One of the most serious offences under the road traffic acts. It is also one of the most heavily challenged. A conviction for drink driving carries a mandatory disqualification from driving of at least one year. 


Drink Driving as an offence is peculiar in the sense that it is one of the few exceptions in the criminal law (certain Revenue and Misuse of Drugs offences aside) where the Defendant is required by law to give evidence against themselves.


It is fundamental precept of common law jurisdictions like Ireland that an accused person is not required to give evidence against themselves or volunteer documentary or other evidence that might assist the State in bringing a prosecution against them. 


Drink driving is fundamentally different. If you are arrested for drink driving you will be required by a member of An Garda Siochana to provide either a specimen of your breath, blood or urine. This requirement is mandatory: you must provide a specimen, as if you do not, this will be treated as a separate offence of “Failing and/or Refusing to Provide a Specimen”.

If you are found guilty of failing to provide a specimen you will be disqualified from driving for 4 years.   


The reason why the Oireachtas passed laws requiring that people arrested on suspicion of drink driving be mandated to provide specimens was purely on public policy grounds: it was in the public interest that motorists who drove while having consumed alcohol or some other intoxicant be regulated.  


However, if the State requires you to give evidence against yourself in the form of a blood, breath or urine specimen, then the Court requires a correspondingly high degree of compliance with the law on behalf of An Garda Siochana.

In effect this means that in many courts Judges require strict compliance by the Gardai with all the myriad elements of the drink driving process and will take a unfavourable view if the strict protocols mandated by the governing legislation are not followed.


It’s a story.


Drink driving is also a story. It’s a story about what happened to you on the day or night that you were arrested, about where you were travelling to, about where you had come from, about how well you were driving, about being pulled over by the side of the road by the Gardai, about what the Guard said to you at the roadside.


It’s about being asked to blow into an apparatus, about being arrested, about feeling shocked, about the conversation you had with that Guard, about the drive back to the Garda station, about being introduced to somebody called the Member-in-Charge.

It's about the strangeness of the place, about feeling a little scared, about being told something about being required to blow into an Intoxilyser machine or that maybe a doctor was being called to attend the station.

It’s about being asked to either blow into the Intoxilyser machine twice, or being told that you must provide either a sample of blood or if you like, a specimen of your urine, about being told that a failure or refusal to provide the sample or specimen is a criminal offence and can lead to a possible jail sentence or fine or both, about being led to a place called the Doctor’s Room.


It's about the strangely antiseptic smell of the place, about the conversation you had with the doctor, about rolling up your sleeve so that the doctor could take the sample of blood with a syringe or maybe being asked to provide a sample of urine into a plastic jug provided to you by the Guard.

It's about watching the sample of blood or urine being placed into two separate glass vials, being packaged into a box that is sealed in your presence, about being led from the doctor’s room to the public office, about being handed your property back by the Member in Charge, about being released from custody.


Defending a drink driving prosecution in court is all about telling a story too. And the court is interested to know this story. Yes, the court must apply the law, that’s mandatory, but the court won’t apply law to something that is patently absurd or which doesn’t make sense in any reality.

If the story you’re telling -or the story that the prosecution is telling- simply doesn’t make sense in any reality, then that story will be discounted by the court.


Detail, Detail, Detail…


You’ve got a story, a story of what happened when you were arrested. Write that story out on good old-fashioned paper with a good old-fashioned pen. Recount - from minute one - where you were going that night, what time it was, what you were wearing, an endless procession of detail.

It may well be the case that you had consumed alcohol, but consuming alcohol while driving is not illegal: consuming so much alcohol that you become impaired because of its effects is illegal.


Prepare that story with great depth. Do it right away, right now. With the passage of time, memory fades; we forget things, that’s normal. So, write it out right now, today.

This is my greatest tip for you: devote a lot of time to this, include every conceivable comment and event, no matter how minor, and write it down.


You won’t get it all down in writing on the first occasion, or even the second, but over a couple of days snippets of information will trickle back into your mind, events buried in your subconscious will present themselves. When they do, drop what you’re doing and write them down or type them as a note in your mobile phone and include them in your written account later on.

Keep adding to that account. Don’t worry about including things that you think might be irrelevant: that’s something for your lawyer to disregard if they choose but give them the rich texture of what happened that day. 


How Alcohol is Processed


When alcohol is absorbed into the body it passes from the stomach into the small intestine. Here, it gets absorbed by the blood and transposed throughout the body.

Alcohol moves rapidly through the body and can reach and affect the central nervous system even in small concentrations. The more alcohol ingested, the more it will impact the central nervous system. It will alter the functioning of, and act as a depressant on, the central nervous system.


Alcohol impairs each of the functioning systems of the body differently. Alcohol acts to impair motor skills, decrease inhibitions, alter judgment and body control, induce confusion, vomiting, fatigue and - in extreme cases - respiratory arrest.


Alcohol enters the body through absorption. This is the first stage of a three-stage process of absorption, distribution and elimination. The three processes happen simultaneously.


Alcohol Absorption


Absorption of alcohol is the process by which alcohol is transferred from outside the body to the stomach, small intestine and then throughout the body through the bloodstream. Once ingested, alcohol is constantly absorbed into and eliminated from the body. The rate of absorption is variable.

It is affected by many factors. These includes the presence of food in the stomach, food composition, the alcohol concentration of the beverage consumed, the rate of consumption, uptake from the stomach and duodenum, emotional state, and the time of day.


Ingested alcohol not yet absorbed from the stomach and intestines has no neurological effects. This means that it cannot cause driving impairment.

Conversely, fully absorbed alcohol may cause driving impairment. The timeframe in which alcohol is absorbed into the bloodstream and the corresponding volume absorbed are important in predicting an ultimate blood alcohol concentration. 


Alcohol Content 


Alcohol Content (%)

Beers (lager)

3.2 – 4.0






6.0 – 8.0

Malt liquor

3.2 – 7.0


14.0 – 16.0

Table wines

7.1 – 14.0

Sparkling wines

8.0 – 14.0

Fortified wines

14.0 – 24.0

Aromatized wines

15.5 – 20.0


40.0 – 43.0


40.0 – 75.0


40.0 – 50.0


40.0 – 48.5


40.0 – 95.0


45.0 – 50.5

The gastrointestinal tract is the main source for absorbing alcohol, although it is absorbed by different parts of the body through blood diffusion. 

Also, the small intestine has a large surface area. It is the most efficient part of the tract for alcohol absorption. In a person with an empty stomach, peak blood alcohol concentrations can expect to be achieved, on average, between 45 to 90 minutes after consumption has begun.

This depends upon the quantity consumed as well as the constituents of last meal. For example, those with a full stomach can exhibit peak blood alcohol concentrations between one and six hours after consumption has begun.


The Effects of Alcohol on the Body 


What if I Eat a Large Meal?


Some have argued that ingestion of food will slow the absorption of alcohol into a person’s bloodstream.

They argue that pyloric valve (located at base of the stomach and regulating flow of food into the small intestine) will close off the bottom of the stomach to contain the food ingested.

This blocks the alcohol from reaching the small intestine. The alcohol will still absorb through the lining of the stomach. But, this process is much slower, and the alcohol suppressed within the stomach gets eliminated from the body at a faster rate.


However, others argue that rather than speeding up the absorption of alcohol, food may actually slow it down, as the body has to contend with absorbing significant quantities of food, as well as alcohol at the same time, thus making the absorption of alcohol more inefficient (see Drink Driving Myths below). 




Any medications that you are taking invariably increase the effects of alcohol, so be sure to consult your doctor before drinking and taking medication. Some medications will react violently when combined with alcohol, and antibiotics may become ineffective when taken in combination with alcohol. 


Types of Alcohol


The different types of alcohol that a person ingests can affect the consumption rate due to the difference in the actual concentrations of alcohol in different alcoholic beverages.

So, if a drink has an alcohol concentration between 10% and 30% such as malt liquors, wine and gin, they get absorbed more quickly than those above 30% and below 10%.

This often plays a role in the increasing blood alcohol level after a person ingests a shot prior to leaving the social event. The shot will be absorbed much slower than the beer they may have been drinking, and may increase a person’s blood alcohol level while the person is in Garda custody.


Those drinks with lower alcohol tend to get missed by the body while in the gastrointestinal tract and tend to be absorbed at a slower rate.

Large quantities can delay the process of food leaving the stomach and entering the small intestine i.e. gastric emptying. Higher amounts tend to irritate the mucous membranes causing increased secretion of the mucous and again slowing the process of gastric emptying.


Therefore, two people with similar body types can drink the same amount of alcohol but if the individuals are of different weights, one will have a larger percentage of water in the body and therefore will become intoxicated less quickly.

An individual with more muscle mass will most likely be less affected than someone with a higher body fat content due to the fact that fatty tissue does not contain very much water and will therefore not absorb much of the alcohol.




At any particular blood alcohol content, a driver may face significantly less impairment than another due to a greater tolerance of the effects of alcohol. For this reason, a driver’s apparent sobriety as seen through an obvious lack of impairment or a demonstration that the driver could perform tasks in a sober manner, sometimes may be used as evidence to rebut an incriminating blood alcohol test result.

In other words, though you may have a blood/urine or breath-alcohol level that exceeds the legal limit, you may not exhibit the classic signs of impairment i.e. eyes glazed, slurred speech, unsteadiness on feet.


Drink Driving Myths. 


Q. Can you have one pint and drive? 


A. As a rule of thumb, two pints of regular-strength lager or two small glasses of wine would put you over the limit. But this is not a catch-all rule. Factors like your weight, sex, metabolism and how much you have eaten all contribute to how your body processes alcohol. In effect, everyone has different limits. Just one glass of wine or a pint of beer could put you over the drink-driving limit.


Q. Can I drive after one glass of wine?


A. A glass of wine can contain between one and a half to three units, depending on the strength and the size of the glass. Some people could be okay to drive after one or two drinks while some may find themselves over the limit after just one.


Q. How long does it take to get alcohol out of your body?


A. It takes time for alcohol to leave your system. On average, it takes about one hour for the body to eliminate one standard drink. Individuals who have higher tolerances to alcohol, such as people with alcohol addiction, may eliminate alcohol more quickly.


Q. If I eat plenty of food and drink plenty of water, I’ll be fine, right?


A. Not necessarily. There is some evidence to suggest that eating food actually slows down the body’s ability to process alcohol quickly. Eating can help you sober up over the long run, but it won't help you beat a blood, urine or breath test.
People have tried eating strong foods like onions and breath mints and drinking mouthwash, but all to no avail. When you blow into a breathalyzer, the device will still be able to read the alcohol in your breath.


Q. How long does alcohol stay in your system before driving?


A. Alcohol is a depressant that has a short life span in the body. Once alcohol has entered your bloodstream, your body will begin to metabolize it quickly at a rate of 20 milligrams per decilitre (mg/dL) per hour. 


Q. Is it zero tolerance in Ireland?


A. The Road Traffic Act 2010 sees the general drink-driving limit reduced from 80mg of alcohol per 100ml of blood to 50mg. It means that just one alcoholic drink — a pint of beer, a glass of wine or a single measure of spirits — could push many motorists over the legal limit.


Q. How do I appeal a drink driving charge?

A. If you have been convicted of drink driving in the District Court you may appeal the conviction to the Circuit Court. The appeal must be lodged within 14 days of your conviction and the appeal will be heard by a different Judge from the one who heard your case in the District Court.