Drink and drug driving

Driving impaired by alcohol or drugs remains one of the biggest contributors to road trauma in Western Australia, with an average of 32 people killed in alcohol related crashes every year.

Last updated: 19 November 2024

An image of two people standing in front of a car, with the two people actually being two versions of the same person, talking to themselves to talk themselves out of drink driving. There is a text bubble that reads 'Yeah, nah, I could use my licence. Drink drive? Nah, not worth it.'

Alcohol and drugs increases the risk of a crash by affecting your ability to make safe decisions and judgements on the road.

Application of drink and drug driving laws

Western Australia’s drink and drug driving laws don’t just apply to people driving cars on roads. The laws also apply to people driving or riding:

any motor vehicle as defined in section 4 of the Road Traffic (Administration) Act 2008 including:
- eRideables
- motorised mobility scooters
- motorised wheelchairs
- motorcycles and quad bikes
- tractors and agricultural vehicles
on roads, paths, tracks, carparks and any other place the public can access.

If you plan to drink, plan not to drive. You could be over the limit and not know it. It's difficult to try and determine your own blood alcohol concentration (BAC) level. Your BAC is affected by several factors, including:

The amount of alcohol you drink.
The period over which alcohol was consumed.
Your body mass.
Whether or not you have eaten.
Your fitness level and health of your liver.

If you do have a drink, as a guide:

Men should not drink more than 2 standard drinks in the first hour and 1 standard drink every following hour.
Women should not drink more than 1 standard drink every hour.
A standard drink contains 10 grams of alcohol
Men and women should not drink more than 4 standard drinks per day, and no more than 10 per week.

Note: Learner and provisional drivers must have a zero BAC when driving.

How Much is a Standard Drink?

Type	%Alc/Vol	Standard Drinks
Mid strength beer glass	3-4%	0.8 standard drink per 285 ml
Mid strength beer can	3-4%	1 standard drink per 375 ml
Wine	10-14%	1 standard drink per 100 ml
Spirits	37-43%	1 standard drink per 30 ml
Pre-mixed drinks	5%	1.5 standard drinks per 375 ml
Full strength beer glass	4-6%	1 standard drink per 285 ml
Full strength beer can	4-6%	1.5 standard drinks per 375 ml

Infringements for Drink Driving Offences

If you are caught driving with a Blood Alcohol Content (BAC) equal to or above 0.05 and less than 0.08, for the first offence, you can pay an infringement to avoid being prosecuted in court. If you are caught a second or subsequent time, you cannot be dealt with by way of infringement. Instead, you will have to appear in court and will receive a fine up to $2000, be disqualified from driving for a minimum of six months, and may be required to participate in the alcohol interlock scheme.

For court penalties, see the tables in the next section.

BAC	Infringement	Demerits
≥ 0.05 but < 0.06	$1,000	3
≥ 0.06 but < 0.07	$1,000	4
≥ 0.07 but < 0.08	$1,000	5

Court Penalties for Drink Driving Offences

The following tables show the court penalties for drink driving offences. The penalties in these tables represent drivers who held a full licence at the time of the offence.

BAC ≥ 0.05 but < 0.07	Court Penalty
First Offence	$1,250 (max) (licence disqualification at Court's discretion)
Second Offence	$1,250-$2,000 and 6 months disqualification (min)
Subsequent Offence	$1,250-$2,000 and 8 months disqualification (min)

BAC ≥ 0.07 but < 0.08	Court Penalty
First Offence	$1,250 (max) (licence disqualification at Court's discretion)
Second Offence	$1,500-$2,000 and 8 months disqualification (min)
Subsequent Offence	$1,500-$2,000 and 10 months disqualification (min)

BAC ≥ 0.08 but < 0.09	Court Penalty
First Offence	$750-$2,250 and 6 months disqualification (min)
Second Offence	$1,600-$2,250 and 8 months disqualification (min)
Subsequent Offence	$1,600-$2,250 and 10 months disqualification (min)

BAC ≥ 0.09 but < 0.11	Court Penalty
First Offence	$850-$2,250 and 7 months disqualification (min)
Second Offence	$1,700-$2,250 and 10 months disqualification (min)
Subsequent Offence	$1,700-$2,250 and 13 months disqualification (min)

BAC ≥ 0.11 but < 0.13	Court Penalty
First Offence	$1,000-$2,250 and 8 months disqualification (min)
Second Offence	$1,800-$3,000 and 14 months disqualification (min)
Subsequent Offence	$1,800-$3,000 and 17 months disqualification (min)

BAC ≥ 0.13 but < 0.15	Court Penalty
First Offence	$1,150-$2,250 and 9 months disqualification (min)
Second Offence	$2,400-$3,750 and 18 months disqualification (min)
Subsequent Offence	$2,400-$4,500 and 30 months disqualification (min)

BAC ≥ 0.15	Court Penalty
First Offence (no relevant prior convictions)	$1,700-$3,750 and 10 months disqualification (min)
First Offence (previously convicted of a drink driving offence involving ≥ 0.08 BAC)	$2,400-$3,750 and 18 months disqualification (min)
First Offence (previously convicted of a polydrug driving offence involving ≥ 0.08 BAC)	$2,700-$3,750 and 27 months disqualification (min)
Second Offence	$3,150-$5,250* and 30 months disqualification (min)
Subsequent Offence	$3,150-$7,500** and disqualification for life

*Alternative to fine for second offence is 9 months imprisonment
**Alternative to fine for third and subsequent offences is 18 months imprisonment

Zero BAC Drivers

In Western Australia, some drivers are subject to a zero Blood Alcohol Content (BAC) when they are behind the wheel. Penalties apply to those drivers who exceed the zero BAC limit.

A zero BAC applies to:

Novice Drivers
Holders of Extraordinary licences
Recently Disqualified Drivers
Drivers of:
- vehicles exceeding 22.5 tonne gross combination mass (GCM)
- vehicles carrying dangerous goods (when such goods are being carried)
- buses (while carrying passengers where the vehicle is equipped to carry more than 12 adults including the driver)
- small charter vehicles (when carrying passengers for hire or reward)
- taxis (when carrying passengers for hire or reward)

Offence	Infringement	Demerits	Court penalty
BAC > 0 but < 0.02	$400	3 Demerits	$400-$750
BAC ≥ 0.02 but < 0.05	-	3 months disqualification (min)*	$400-$750

*If a novice driver is disqualified, the licence is cancelled. For all other licence holders, a disqualification will result in a suspension.

WA Alcohol Interlock Scheme

An alcohol interlock is a breath testing device which, when installed in a vehicle or motorcycle, prevents it from being operated if a breath sample reads above a certain amount of alcohol.

The WA Alcohol Interlock Scheme aims to reduce the road safety risk posed by drink drivers. It is a mandatory, user pays, performance-based scheme in which alcohol interlock devices provide separation of drinking and driving behaviour.

In WA, interlocks are mandatory for drivers who:

Are convicted of driving with a BAC 0.15 or over.
Are convicted of dangerous driving causing death, bodily harm or grievous bodily harm, where they're under the influence of alcohol to such an extent as to be incapable of having proper control of a vehicle.
Commit a second drink driving offence of any kind within 5 years.
Fail to comply with a request to provide a breath sample to a member of WA Police.

The Department of Transport website provides more information on the Alcohol Interlock Scheme.

Different drugs have different effects on your driving skills and ability to make good decisions on the road.

Some drugs such as marijuana, slow your reaction time and impair your ability to judge speed and distance.

Other drugs such as amphetamines and cocaine can result in erratic, reckless and aggressive driver behaviour.

Some prescription medications can have side effects that impair your driving skills and can result in drowsiness and slow your reactions. Talk to your GP or pharmacist about whether your prescription or over the counter medication could affect your ability to drive safely. For more, see our Medicines and Driving Fact Sheet (PDF 125kb).

Taking any drug before driving increases the risk of a crash that results in road trauma.

Driving with Specified Drugs in Oral Fluid

Police have the power to stop drivers suspected of driving while impaired by any drug. Those found with specified drugs (Cannabis, Ecstasy or Meth) in their oral fluid can be charged with the offence of Driving with Specified Drugs in Oral Fluid.

Driving with Specified Drugs in Oral Fluid	Court Penalty
First Offence	$1,250 (max) and 3 Demerits
Second OR Subsequent Offence	$1,250-$2,000 and 6 months disqualification (min)

Drug Impaired Driving

The more serious offence of Drug Impaired Driving, or Driving under the Influence of Drugs, applies to drivers found to be so impaired by either prescription or illicit drugs that they are not capable of proper control of a vehicle. This applies where police have evidence of suspicious or erratic driving behaviour and where that suspicion is confirmed following a driver assessment and/or blood tests.

Drug Impaired Driving	Court Penalty
First Offence	$1,700-$3,750 and 10 months disqualification (min)
Second Offence	$3,150-$5,250* and 30 months disqualification (min)
Subsequent Offence	$3,150-$7,500** and disqualification for life

*Alternative to fine for second offence is 9 months imprisonment
**Alternative to fine for third and subsequent offences is 18 months imprisonment

Drug Driving Prohibition Notices

WA Police will issue drivers who test positive for specified drugs (Cannabis, Ecstasy or Meth) or refuse a roadside drug test with a prohibition notice which bans them from driving for 24 hours.

Breaching the prohibition notice is an offence. Police may issue an infringement notice with a penalty of $600.

Motorists who refuse to provide samples for drug and alcohol testing will be hit with the highest penalty for the relevant substance impaired driving offences (drink driving, drug driving, or drink and drug driving).