Alcohol's impact on driving
Even in small amounts, alcohol impairs driving ability and as blood alcohol concentration (BAC) increases the functioning of vital processes for safe road use, such as vision and motor skills, becomes progressively more impaired. In short, any amount of alcohol increases the risk of involvement in a road traffic collision.
Alcohol has been shown to impair driving performance at blood alcohol concentrations as low as 0.02% [60,61] and well before the driver or observers are able to detect signs of intoxication [62]. Most countries maintain maximum legal blood alcohol concentration levels for non-probationary drivers (e.g., 0.05%, 0.08% [58]) that are higher than levels now known to significantly increase crash risk.
Drink driving legislation
The central legislation concerning road safety is the Road Traffic Act 1961. This legislation has been updated an number of times, including the Road Traffic Act 2006, the Road Traffic Act (No.2) 2011, the Road Traffic Act 2014, the Road Traffic Act 2016, the Road Traffic (Amendment) Act 2018 and the Road Traffic Act 2024. The Road Traffic Act 2006 gave Gardaí a range of powers to deal with drink driving, such as the power to breathalyse any driver stopped at a mandatory alcohol checkpoint without first needing to form an opinion in relation to the state of the driver. This is known as random breath testing.
The Road Traffic Act (No.2) 2011, made it mandatory for Gardaí to conduct a breath test where they believe a driver has been drinking, and at the scene of a crash where someone has been injured and requires medical attention. The Road Traffic Act 2014 allowed for a specimen of blood to be taken and tested for alcohol and other drugs from a driver who is incapacitated following a road traffic collision. Upon regaining capacity, any refusal by the driver to consent to the issuing of a certificate of the test result based on the specimen is an offence. Under the Road Traffic Act 2016, Gardaí can conduct drug tests at the roadside or in Garda stations.
The provisions of the Road Traffic (Amendment) Act 2018 include mandatory driving disqualification plus a €200 fine for a first drink-driving offence if a motorist has a blood alcohol concentration (BAC) above 50 mg/100 ml and ensures that all drivers found to have a BAC above 50 mg/100 ml will receive a driving disqualification, without exception. This removes the concession in previous legislation by which some drink-drivers were able to obtain penalty points instead of a disqualification.
The Road Traffic Act 2024 amends the rules on testing for intoxicants to provide for drug testing to align with current rules on alcohol testing.
Impact of alcohol on fatal collisions
Alcohol impairment impacts road safety and drink driving is a major factor in road collisions and fatalities on the road. Analysis of coronial data found that 37% of driver fatalities (2015-2019) with a toxicology result available, had a positive toxicology for alcohol. Almost one in three crash deaths in Ireland is alcohol-related.
A study in France found that drivers under the influence of alcohol are 17.8 times more likely to be responsible for a fatal accident, and the proportion of fatal accidents which would be prevented if no drivers ever exceeded the legal limit for alcohol is estimated at 27.7%.
What is the Irish drink driving limit?
The legal Irish blood alcohol limits for professional, learner and novice drivers are:
- 20 milligrammes of alcohol per 100ml of blood
- 27 milligrammes of alcohol per 100ml of urine or
- 9 microgrammes of alcohol per 100ml of breath.
The legal Irish blood alcohol limits for fully licenced drivers in Category B are:
- 50 milligrammes of alcohol per 100ml of blood
- 67 milligrammes of alcohol per 100ml of urine or
- 22 microgrammes of alcohol per 100ml of breath.
What is the penalty for drink driving?
Drink driving / driving under the influence (DUI) is a serious offence. The penalties for driving with alcohol in your system vary depending on the type of driver and the concentration of alcohol.
Administrative penalty system
You will be issued with a fixed penalty notice if you hold a valid licence or permit at the time of the offence and your alcohol level is below a certain limit. If you pay the fine stated on the notice within 28 days, the additional penalty will be imposed but you will not have to go to court. You are not eligible for a drink driving fixed penalty notice if you have received a similar notice within the previous 3 years. The alcohol limits and penalties applied under the fixed penalty notice scheme are:
| Driver type | Concentration of alcohol | Fine | Additional penalty |
| Experienced drivers | a) 50+mg to 80mg of alcohol per 100ml of blood (b) 67+mg to 107mg of alcohol per 100ml of urine (c) 22+mcg to 35mcg of alcohol per 100ml of breath | €200 | 3 months disqualification |
| Experienced drivers | (a) 80+mg to 100mg of alcohol per 100ml of blood (b) 107+mg to 135mg of alcohol per 100ml of urine (c) 35+mcg to 44mcg of alcohol per 100ml of breath | €400 | 6 months disqualification |
| Other drivers | (a) 21mg to 80mg of alcohol per 100ml of blood (b) 27+mg to 107mg of alcohol per 100ml of urine (c) 9+mcg to 35mcg of alcohol per 100ml of breath | €200 | 3 months disqualification |
Court system
If you have to go to court the disqualification periods for drink driving convictions are as follows:
| Concentration of alcohol | First offence (period of disqualification) | Second offence (period of disqualification) |
(a) 50+mg to 80mg of alcohol per 100ml of blood (b) 67+mg to 107mg of alcohol per 100ml of urine (c) 22+mcg to 35mcg of alcohol per 100ml of breath | 6 months | 1 year |
a) 80+mg to 100mg of alcohol per 100ml of blood (b) 107+mg to 135mg of alcohol per 100ml of urine (c) 35+mcg to 44mcg of alcohol per 100ml of breath | 1 year | 2 years |
(a) 100+mg to 150mg of alcohol per 100ml of blood (b) 135+mg to 200mg of alcohol per 100ml of urine (c) 44+mcg to 66mcg of alcohol per 100ml of breath | 2 years | 4 years |
| (a) Exceeding 150mg of alcohol per 100ml of blood (b) Exceeding 200mg of alcohol per 100ml of urine (c) Exceeding 66mcg of alcohol per 100ml of breath | 3 years | 6 years |
The minimum disqualification on a first offence if you are convicted of being too intoxicated to be in proper control of your vehicle is 4 years. The minimum disqualification for a second or subsequent offence is 6 years. The judge has the discretion to increase these penalties. The maximum penalty exclusively for drink driving is €5,000 or 6 months in prison or both.
How long does it take for alcohol to leave your system?
It takes most people 1 to 2 hours to process 1 standard drink. After you stop drinking, the alcohol levels in your system can continue to rise for up to 3 hours. Nothing can speed up the metabolism of alcohol by your body. For example, drinking water or coffee, eating or having a shower will not affect how long alcohol stays in the system. For more information on how alcohol affects your ability to drive see the HSE’s website.
How long after drinking can I drive?
Because it takes most people 1 to 2 hours to process 1 standard drink, you should wait at least 1 hour per standard drink consumed after stopping drinking. One standard drink – which is enough to put someone over the limit – is the equivalent of a glass (half pint) of beer, a small glass of wine (100ml) or a pub measure of spirits (35.5ml). If planning to drink, you should plan not to drive.
The Road Safety Authority’s drink driving statistics from January 2024 show that, in the previous 12 months, one in 10 Irish motorists have driven after consuming alcohol. The total number of arrests for driving under the influence (DUI) of alcohol or drugs for 2023 was 8,863, according to An Garda Síochána. Almost half of all arrests for driving under the influence of an intoxicant take place between midnight and 6am. One in 10 DUI arrests are made between 8am and 2pm, with a peak on Sundays.
What needs to happen?
It is essential that road safety strategy should have a public health perspective. Given the current high level of drink driving in Ireland there is a need for a government-led drink driving taskforce which includes alcohol policy professionals, psychologists, road safety engineers, men’s health experts, gardai, mental health experts and communication experts. Areas which should be examined include:
- Implementation of comprehensive public health measures of controls on pricing, marketing and availability of alcohol to reduce overall level of alcohol consumption in Ireland. These policy ‘best buys‘ will also reduce drink driving, deaths and injuries on roads. For example there is evidence across the EU that a 10% increase in alcohol prices leads to a 7% reduction in road deaths.
- Increase, sustain and have visible enforcement of mandated alcohol testing checkpoints by Gardai. Greater enforcement will increase the risk of drivers being caught drink driving, shift consumption and save lives.
- Monitor and regularly publish the volume of driver alcohol testing, including mandatory alcohol testing, undertaken by An Garda Síochána on a county and national basis.
- The alcohol ignition interlock system should be introduced. The alcohol ignition interlock is a personal alcohol breath-test device for drivers that automatically prevents a vehicle from starting if the individual is over the limit.
- Offenders should be provided with access to treatment for alcohol use disorder.
- To find out more about drink-driving and wider road safety issues please visit the Road Safety Authority’s website.
