Drink Driving Limits: How Long You Should Wait Before You Drive After Drinking

by EzLicence Last updated

Drink Driving Limits in Australia

How Long Is It Safe to Drive After Drinking

Australians are a social bunch. Enjoying the beautiful weather around a barbecue with friends is part of our culture. Coupled with that, sometimes unintentionally, you have one or two drinks to appreciate a celebration or occasion. 

From a very young age, before even starting to drive, we inherently know that drink driving is taboo.      

Particularly as we head into silly season, being mindful of our own safety and that of others on the road is foremost. “How long after drinking is it safe to drive” is a question we may all admit to having asked ourselves at least once. 

The drink driving limit in Australia is a variable subject, with many considerations and no real straight answer.

What defines drink driving?

There are two major offences with drink driving. One is exceeding the Prescribed Concentration of Alcohol (PCA) and Driving Under the Influence (DUI).

Exceeding PCA is the most common form. PCA charges are common if you have been caught during a police breath test, or by other means where there is a specific reading of the concentration of alcohol in your blood at the time.

For full license holders, the maximum BAC (Blood Alcohol Concentration) is 0.05%. For learners, provisional or probationary license holders' any measure of alcohol is a breach of licence conditions. In addition, if the level exceeds 0.05% you face charges.

In circumstances where a person is suspected of having used or attempted to use a motor vehicle on a road or road related area whilst intoxicated and Police were not able to obtain a breath or blood sample, it is open to them to charge the person with DUI.

This can be because too much time has elapsed between you driving a vehicle and the breath test being administered, because police didn’t abide by standard procedures when performing the breath test, or because the reading was inconclusive. This is an offence based around the impaired ability to control a vehicle. 

What’s the risk?

The BAC (Blood Alcohol Content) of 0.05% is the researched limit of a tolerable amount of alcohol content to still safely operate a vehicle. So really, how long after drinking is it safe to drive? The general rule of thumb is that 2 standard drinks in the first hour raises your BAC (Blood Alcohol Concentration) to 0.05%. 
One standard drink for each hour you are socialising after that can continue that 0.05% average.
For the average human body to process safely in one hour, Australians classify a standard drink as 10 grams of alcohol (equivalent to 12.5ml of pure alcohol). 
There is a “quick formula” that takes the number of hours since your first drink and add one to it. But. And this is a big But. That is not always accurate.

How long is it safe to drive after drinking?

There are just so many variables in blood alcohol concentration for there to give a straight answer.
Whether you are male or female, your weight, what type of alcoholic drinks, the time that has passed, if you’ve eaten and if you are taking any supplements or medications are some factors in how quickly you metabolise alcohol.  
Fitness and age are factors too. No one wants to see the teenage drink driving statistics in Australia increase, let alone the adult drink driving statistics.

What’s the penalty?

Laws and penalties vary from state to state, so ensuring you are fully aware of your responsibilities is crucial. If convicted of an offence, the court will decide your driving disqualification time frame depending on level of intoxication, if you have had an accident or history of drink driving. In extreme cases or histories, they may enforce prison time. Consequences from loss of licences can cause loss of employment if your job requires you to drive.

Keep the kids out of it.

Drink driving is reckless at the best of times. Driving under the influence with children takes it to a whole other level. It is an offense if you attempt to drive any motor vehicle with a child under 16 years. You will receive a disqualification period, fines, and need to prove your changed behaviours before the court grants your license back.

All the tools could still break the rules. 

There are cheap breathalysers you can purchase at convenience stores and gas stations. While they may be close to the money, chances are the technology they use has already dated and compromises the accuracy of the results. While there are many apps, calculators and ‘rules of thumb’ out there, the fact remains that every one of us will metabolise alcohol differently. The most accurate result you will get is that of the police officers’ test. How long after drinking is it safe to drive is not an answer given by a website, app or device. For the safety of yourself and other road users, if in doubt, sleep it out. Or catch a taxi.

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