If you have any questions please contact our ADT breathalyser specialists on 02 4577 9347

How does alcohol affect your driving?

You don’t have to be drunk to be affected by alcohol.No one drives as well as usual after drinking alcohol, even though some people may look and act as though they are unaffected. Alcohol is a depressant drug that affects most areas of the brain.


  • Slows brain functions so that you can’t respond to situations, make decisions or react quickly.
  • Reduces your ability to judge how fast you are moving or your distance from other cars, people or objects.
  • Gives you false confidence – you may take greater risks because you think your driving is better than it really is.
  • Makes it harder to do more than one thing at a time – while you concentrate on steering, you could miss seeing a red light, cars entering from side streets or pedestrians.
  • Makes you feel sleepy or fatigued.
You cannot compensate for the effects of alcohol on your brain.

Staying under the limit

Estimating your BAC is often inaccurate because:

  • The alcohol concentration of drinks vary from 2.5 percent (eg light beer) to over 40 percent (eg vodka, whisky).
  • Beer may be served in pints, schooners or middies.
  • Wine glasses may vary in size from 100 to 280mls. Many other drinks come in non-standard sizes.
  • Factors such as your gender, size, weight fitness, health and liver function will all affect your BAC. Also, the rate at which alcohol is eliminated from your system varies from person to person. So, don't try to estimate your BAC. Measure it.
But remember:

  • Alcohol must not be consumed for at least 15 minutes before testing because alcohol in your mouth will give an artificially high reading.
  • Your BAC will rise for up to 2 hours after you stop drinking.
  • After a night of Drinking you may still be over the limit the next day. You should take another test in the morning.