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The effects of alcohol on both physical and mental functioning make driving hazardous—alcohol is involved in around one-third of all road deaths.
The Road Transport Act 2013 (NSW) Part 5.1 deals with road offences that involve alcohol and/or drugs. The procedures for testing for alcohol or other drug use by drivers and other road users are covered in Schedule 3 to the Road Transport Act 2013.
Driving under the influence
It is an offence under section 112 of the Road Transport Act 2013, to drive or attempt to drive ‘under the influence’ of a drug or alcohol. A full list of drugs can be found in Schedule 1 of the Drug Misuse and Trafficking Act 1985 (NSW). Proof of this offence requires proof beyond reasonable doubt that the driver was intoxicated to some degree by the drug or alcohol.
If the police reasonably suspect that a person is driving under the influence of a drug, they have the power to take them to a hospital for a blood or urine test for the presence of drugs, under the supervision of a doctor.
It is an offence to refuse to submit to a blood test or a urine test in these circumstances. It is likewise an offence to wilfully alter the amount of drug in your blood or urine before having the test, unless it is more than two hours since you were driving.
Prescribed content of alcohol
Since the introduction of breathalysers and random breath testing (RBT) for alcohol, drink-driving offences are now much more commonly charged as driving with the relevant ‘prescribed concentration of alcohol’ (PCA).
This in effect bypasses any need to prove intoxication — the presence of alcohol in a person’s system is sufficient evidence for the offence to be proved. Blood alcohol concentration is measured in grams per 100 mL (g/100 mL). For most fully licensed drivers, the prescribed limit is 0.05. For drivers with a learners or provisional licence — L or P-plate drivers—the limit is zero. For people driving heavy vehicles or public passenger vehicles — trucks or buses — and people driving vehicles containing dangerous goods, the limit is 0.02.
The amount of alcohol that can be consumed before a person reaches the legal limit varies considerably from one person to another, and for the same person in different circumstances. There is also a range of offences relating to refusal or failure to submit to a roadside breath testing, providing blood samples and for interfering with samples, set out in Schedule 3 to the Road Transport Act.
Presence of certain drugs
It is an offence under the Road Transport Act 2013 (NSW) to drive with THC (the psychoactive ingredient of cannabis), cocaine, methamphetamine or ecstasy ‘present’ in the driver’s saliva, blood or urine (although only saliva is usually tested).
It is also an offence to drive with morphine present, but this substance will not be detected by saliva swab.
The police have the powers to test drivers for the presence of these drugs. Mobile drug testing (MDT) involves a saliva test using drug screening equipment. If the initial saliva test indicates positive, then the driver must undertake a second saliva swab at a mobile drug bus or police station.
If the second swab shows positive, the police issue the driver with a direction not to drive for 24 hours. If the second swab is negative, the driver is free to go. But the second sample is sent to the laboratory for analysis, whether it is positive or negative. If the laboratory analysis confirms the presence of THC, cocaine, methamphetamine or ecstasy, the driver is issued with a court attendance notice for the offence. It is the analysis by the laboratory, not the roadside test results, which the police rely on as evidence in court.
The offence requires only proof of the presence of one of the three drugs in the saliva sample. It is not necessary for the police to prove any impairment of driving ability. It is a defence to this charge if the driver had an honestly held and reasonably based belief that they did not have any relevant drug present in their saliva at the time of the driving.
As with Random Breath Testing, there are offences for failing or refusing to submit to a saliva test or provide a blood sample in Schedule 3 to the Road Transport Act.
The licence disqualification periods are mandatory, but only on conviction. They can only be avoided if the magistrate deals with the case under section 10 of the Crimes (Sentencing Procedure) Act 1999 (NSW) to impose no conviction for the offence. A person cannot receive the benefit of two section 10 dismissals without conviction in a five-year period, and any subsequent offence will mean mandatory disqualifications apply.
For prescribed content of alcohol offences, the penalties increase with a higher blood alcohol readings. The offences are in ‘ranges’, measured in grams per 100 millilitres of blood or in 210 litres of breath:
- novice range: zero - 0.02
- special range: 0.02 – 0.05
- low range: 0.05 – 0.08
- middle range: 0.08 – 0.15
- high range: over 0.15.
These prescribed limits are set out in section 108 of the Road Transport Act 2013 (NSW). For serious and repeat offences imprisonment is an option.
Police can obtain blood or urine samples from drivers involved in fatal road accidents. Under the Crimes Act 1900 (NSW) a person convicted of driving under the influence of a drug and causing death is liable for a maximum penalty of 10 years' jail (or 14 years if there are circumstances of aggravation such as speeding).
The information on this page was originally published in The Quick Guide to Drugs and Alcohol. It has been updated to reflect changes to the law.