Alcohol, drugs and driving

Safe driving requires good judgement and sharp concentration. 

You need to react quickly to changing situations on the road. 

Drinking alcohol and taking drugs reduces your ability to drive safely.

They can affect your: 

  • vision
  • speed and distance judgments
  • reflexes and reaction times
  • decision-making
  • concentration.

Drinking alcohol also increases risk-taking behaviour by giving a driver a false sense of confidence.

Drinking and driving

It's best that you don't drink alcohol before driving.

If you are over the legal blood or breath alcohol limit, you could face drink-driving penalties, and put you and other road users at risk.

What is a blood or breath alcohol concentration (BAC)

A blood or breath alcohol concentration (BAC) is the amount of alcohol in your body.

Your blood alcohol concentration is measured in a percentage per 100ml of blood.

You breath alcohol concentration is measured in a percentage per 210 litres of breath exhaled.

For example, a BAC of 0.05% means your body contains 50mg of alcohol per 100ml of blood.

Standard drinks and driving

As soon as you start drinking, the level of alcohol in your blood or breath starts to rise.

A standard drink contains about 10g of alcohol.

As a guide one standard drink includes any of the following:

  • 100ml of wine
  • 375ml mid strength beer
  • 285ml of full strength beer
  • 30ml of spirits.

The level of alcohol in your blood or breath is affected by a number of factors including any of the below:

  • amount of alcohol you drink
  • the time over which you drink it
  • your body mass
  • how much food you've eaten
  • your health.

Everyone is different but as a guide:

  • men should not drive if they have drunk more than two standard drinks in the first hour and more than one standard drink every hour after that
  • women should not drink more than one standard drink in an hour before driving.

If you're going to drink, it is safer to arrange a Sober Bob to get you home - read more about Sober Bob below. 

Alcohol limits for drivers in the NT

In the NT you must stay below the blood or breath alcohol limit for your class of driver licence.

Alcohol limit for your class of driver licence

Licence classification0% BACUnder 0.05% BAC
Learner licenceX 
Provisional licenceX 
Full licence (car or rider) on Z conditionX  
Full licence (car or rider) X
Approved driving instructors who are teachingX  
Public passenger vehicle drivers – bus, taxiX 
Coach or heavy vehicle (over 15 tonnes GVM or GCM) driversX 
Dangerous goods vehicle driverX 
Fully licensed drivers from interstate and overseas. X

Definition of alcohol limits

The Northern Territory has four alcohol limits. 

Zero alcohol limit

You will be over this limit if the concentration of alcohol in your blood or breath is more than zero. 

Low range alcohol limit

You will be over this limit and face a drink-driving penalty if the concentration of alcohol in your blood or breath is equal to or more than 0.05% BAC.

Medium range alcohol limit

You will be over this limit and face a drink-driving penalty if the concentration of alcohol in your blood or breath is equal to or more than 0.15% BAC.

High range alcohol limit

You will be over this limit and face a drink-driving penalty if the concentration of alcohol in your blood or breath is equal to or more than 0.25% BAC.

Drugs and driving

It is illegal to drive while under the influence of drugs, including some over the counter and prescription medicines. 

Taking drugs before puts you at risk of injuring or killing yourself, your friends or others. 

Drugs and medications can significantly affect any of the following:

  • driving skills
  • alertness
  • capability
  • vision
  • reaction time.

Drug testing

Random roadside saliva testing will identify the recent use and presence of the following prohibited drugs:

  • THC - the active ingredient in cannabis
  • methylamphetamines - also called ice or speed
  • MDMA - the active ingredient in ecstasy.

If you test positive on the first saliva test, police will require you to submit a second saliva test at the roadside to confirm the presence of drugs. 

The second saliva test will also detect the presence of cocaine, valium and opiates (morphine and codeine).

Blood testing may be used as an alternative if a second saliva test can't be carried out. 

Medicines and over-the-counter drugs

Many prescription and some over the counter medicines can affect your ability to drive and could make you unfit to drive. 

They can affect your concentration, mood, coordination and reactions as a driver.

When you receive a prescription for a drug by your doctor you should ask whether the drug will affect your driving.

Read the label on prescription medication and other over the counter products to check that they do not contain alcohol (also known as ethanol), or contain a warning about possible effects on your driving ability.

Do not drive while taking medicines with a warning label that tells you not to drive.

Do not drive if any medication affects your ability to control a vehicle.

Some medicines that can affect driving include any of the following:

  • pain killers
  • medicines for blood pressure, nausea, allergies, inflammations and fungal infections
  • tranquillisers, sedatives and sleeping pills
  • diet pills
  • cold and flu medicines.

How you can be safe

If you are going to drink or take drugs you must not drive. 

You should plan how you will get home stay overnight or arrange a Sober Bob.

Sober Bob is someone who is willing to get you home safely, they can be the bus driver, taxi driver, mum, brother or friend. 

Know your limits when drinking.

Last updated: 14 September 2016