Driving is a very complex task that requires correct decision-making and total concentration. Research and statistics prove that those who drive under the influence of alcohol, i.e. drink and drive, have a much greater chance of having a car accident.
How much can I safely drink?
There is no absolute safe level of alcohol consumption for competent driving. However, Australia has strict laws about drinking alcohol and driving, with the legal limit set at 0.05 BAC.
The law stipulates that Australian drivers must have a blood alcohol concentration (BAC) of less than 0.05. Australian police are authorised to stop any vehicle and breath test the driver for their BAC at any time.
Random breath testing results show that on average, one in 300 drivers tested exceeds the legal limit.
Research shows that any BAC over the legal limit at least doubles your risk of car crash injury and your risk of involvement in a fatal crash rises sharply.
Alcohol causes more road crashes than any other single factor in Australia. One in four fatal car accidents involves drivers or riders who are above the legal BAC limit of 0.05. In some states of Australia these account for one in three fatal crashes.
Drinking alcohol can affect your driving by:
- Slowing down your reaction time – this can be crucial in an emergency situation
- Dulling your thinking processes, making it difficult to multi-task – an essential skill reducing your attention span – not noticing other drivers and/ or vehicles
- Causing short-term side effects such as blurred vision and reduced hearing – reducing your ability to drive safely and identify driving hazards.
What is BAC?
BAC is a measurement of the amount of alcohol in your body, expressed as grams of alcohol per 100ml of blood. Hence, for fully licensed car drivers the legal limit of 0.05 BAC means 0.05gm alcohol per 100ml of blood. For special licence categories such as learner and probationary drivers, taxi, bus, train and heavy truck drivers, the legal limit is zero (0) BAC or 0.02 (which in practice means no alcohol at all).
A driver’s BAC is measured by a simple breath test procedure. If tested by the police, drivers must be below their allowable legal limit. A glass of champagne (11.5 per cent alcohol), or a 375ml stubby or can of full strength beer (4.9 per cent alcohol) are all 1.5 standard alcoholic drinks.
To keep under the 0.05 BAC limit, males can drink no more than two (2) standard alcoholic drinks in the first hour (10gm of alcohol in each) followed by one (1) standard alcoholic drink every hour after that. However, females can drink no more than one (1) standard alcoholic drink every hour.
Danger increases the more you drink
0.02 to 0.05 BAC – your ability to see or locate moving lights correctly is reduced, as is your ability to judge distances. Your tendency to take risks is increased, and your ability to respond to several stimuli is decreased.
At 0.05 BAC drivers are twice (2) as likely to have a crash as before they started drinking.
0.05 to 0.08 BAC – your ability to judge distances reduces further, sensitivity to red lights is impaired, reactions are slower, and concentration span is shorter.
At 0.08 BAC drivers are five (5) times more likely to have a crash than before they started drinking. At 0.08 to 0.12 BAC – “euphoria” sets in – you overestimate your abilities, which leads you to drive recklessly, your peripheral vision is impaired (resulting in accidents due to hitting vehicles while passing), and your perception of obstacles is impaired. Drivers are up to ten (10) times more likely to have a crash.
How does alcohol affect me?
Alcohol is a drug that slows down your body, both physically and mentally. Excessive drinking affects your judgment, memory and reaction time. It takes much longer for your body to expel alcohol than to absorb it, so you can drink a large quantity of alcohol in the evening and still have alcohol present in your body the next day, affecting your driving and other activities.
It’s important to note that these guidelines are general and a range of factors can influence an individual’s BAC, such as your body size, age, level of fitness, liver health, gender, medication, when you last ate and the type of food you ate.
This page has been developed from material provided by the Centre for Accident Research and Road Safety – Queensland (CARRS-Q). For further information visit: http://www.carrsq.qut.edu.au/