Drink and drug driving laws in South Australia

By the end of this topic you can

• You can state the BAC limit for learners, P drivers, full licence holders and supervising drivers.
• You can explain how random breath and saliva testing works.
• You can describe the main penalty categories and when licence loss is immediate.
• You can plan safe ways home that do not involve driving after drinking.

What you need to know and understand

• Learner, provisional and probationary drivers must have a zero BAC. Any alcohol at all breaches your conditions and leads to disqualification.
• Full licence holders, including qualified supervising drivers, must be under 0.05.
• BAC measures grams of alcohol per 100 millilitres of blood; 0.05 means 0.05 grams in every 100 millilitres.
• Driving with any THC, methylamphetamine, MDMA or cocaine in your saliva or blood is an offence; no minimum amount is needed.
• A BAC of 0.08 or more, drug driving, or refusing a breath or drug test can mean losing your licence on the spot.
• You can still be charged with driving under the influence even below 0.05 if alcohol or drugs affect your control of the vehicle.
• Only time lowers your BAC. Coffee, showers, food or exercise do not.

How testing works

Police can require any driver to take a breath test at any time, including after a crash or a traffic offence, and they can also test a learner's supervising driver. A positive roadside result leads to a second test on another instrument, which is used as evidence.

Roadside saliva tests check for THC, methylamphetamine, MDMA and cocaine. A positive strip leads to a second saliva sample in the drug bus or at a police station, then laboratory analysis. If you are injured in a crash and go to hospital, a blood sample is taken and tested too. Refusing or failing to comply with a breath, drug or blood test is itself a serious offence.

Penalty bands for drink driving

Fines are set by regulation and updated regularly, so check the current figures on the official offences and penalties list rather than relying on older sources.

• Category 1 (0.05 to 0.079): a first offence can be expiated with a fine and 4 demerit points; repeat offences go to court with disqualification.
• Category 2 (0.08 to 0.149): court penalty, 5 demerit points and immediate loss of licence for 6 months on a first offence.
• Category 3 (0.15 or more): court penalty, 6 demerit points, immediate loss of licence for 12 months and an alcohol interlock after disqualification.
• Drug driving: 4 demerit points, and police can take your licence at the roadside.
• For L and P drivers, any alcohol or drug also breaches your licence conditions, adding disqualification on top of the offence penalty.

Medicines and planning ahead

Sleeping tablets, some painkillers, muscle relaxants and antihistamines in cold and hay fever products can affect your driving. Read the label, ask a pharmacist, and do not drive until you know how a new medicine affects you. Never take someone else's prescription.

Before a night out, decide how you will get home: a non-drinking driver, public transport, a taxi, staying over, or a lift from someone you are sure is sober. After heavy drinking you may still be over the limit the next day.

Common mistakes

• Having one drink on Ls or Ps because you feel fine. Your limit is zero, not 0.05.
• Assuming a supervisor can have a few drinks. They must stay under 0.05 and can be breath tested.
• Driving the morning after a big night. Only time removes alcohol from your blood.
• Thinking cannabis used days earlier cannot be detected. Driving with any amount present is an offence.

Test yourself: Drink and drug driving laws in South Australia

Answer each question, then read the explanation. Questions come in a random order each time.

Go deeper

• High-Powered Vehicles and the U Class Licence in South Australia
• Learning to Drive in South Australia
• South Australia Health Professional Reporting