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DrugsAustralia

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Traffic signs
Traffic rules
Australia

231. Drugs

Drugs can seriously affect driving by changing perception, concentration, reaction time, coordination and judgement. Stimulants, cannabis, opioids and other psychoactive substances can each impair driving in different ways, and combining drugs with alcohol or other substances can increase the risk further. The effects may continue even after a person no longer feels intoxicated. Drug-driving laws vary between countries, but drivers should never drive when a substance affects their ability to control the vehicle safely.

How can drugs affect driving?

Drugs can impair concentration, perception, reaction time, coordination and judgement. The effects depend on the substance, dose, individual and whether other substances are also present.

Can cannabis affect driving?

Yes. Cannabis can affect attention, reaction time, coordination and perception, which can make driving unsafe.

Can stimulant drugs affect driving?

Yes. Stimulants can cause overconfidence, agitation, impulsive behaviour and reduced judgement, while their effects may later be followed by fatigue or reduced concentration.

Can drugs still affect you after the main effects have worn off?

Yes. Some substances can continue to affect alertness, coordination or judgement after the strongest effects appear to have passed.

Is combining drugs and alcohol especially dangerous?

Yes. Combining substances can produce stronger or unpredictable impairment and significantly increase the risk of a crash.

How can police test drivers for drugs?

Depending on the country, police may use behavioural observations, saliva tests, saliva analyses or blood tests to detect specified substances.

Are drug-driving laws the same in every country?

No. Some countries prohibit driving above specified drug concentrations, while others focus on impairment or the presence of certain substances. Testing procedures and penalties also vary.

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