Driving Under the Influence (DUI) Charges
Clear advice on how DUI differs from PCA, the penalties, and the Local Court process.
Driving under the influence, created by section 112 of the Road Transport Act 2013 (NSW), is a distinct offence from the more commonly charged drink driving (PCA) offences. Rather than relying on a specific breath or blood alcohol reading, a DUI charge is based on evidence that a person’s ability to drive was actually impaired — by alcohol, an illicit drug, or even a lawfully prescribed or over-the-counter medication — to the point where they were incapable of having proper control of the vehicle.
DUI charges are typically laid where police cannot obtain, or do not rely on, a specific breath or blood reading — for example, where a driver was taken directly to hospital following a crash, where a breath analysis was refused or could not be completed, or where the substance involved (such as a sedating prescription medication) would not be captured by the usual PCA or illicit drug presence testing regime. Because there is no set reading to point to, this offence typically relies on police observations of driving, physical coordination, speech, and behaviour, sometimes supported by expert toxicology evidence.
Because DUI requires proof of actual impairment rather than a specific concentration, it can, in some respects, be more difficult for the prosecution to establish than an equivalent PCA charge, but it also carries no simple, objective reading for the defence to point to in response. The quality and consistency of police observations, any available footage, and expert evidence about the effects of the substance involved are usually central to how these matters are contested.
Penalties
What you could be facing
| Penalty | Maximum | Notes |
|---|---|---|
| Driving under the influence — first offence (s112 Road Transport Act 2013) | A substantial fine and/or a term of imprisonment | Carries an automatic licence disqualification period on conviction, broadly comparable to a mid to high range PCA offence, though the court retains some discretion over the length of the disqualification. |
| Driving under the influence — second or subsequent offence | A higher fine and/or a longer term of imprisonment | Both the maximum penalty and the automatic disqualification period increase for a person with a relevant prior conviction. |
| Aggravating factors | Sentence increased within the applicable maximum | The degree of impairment observed, any resulting collision or injury, and the presence of multiple substances (such as alcohol combined with a sedating medication) are significant considerations at sentencing. |
Possible Defences
Ways this charge can be challenged
Absence of actual impairment
Because DUI requires proof that the accused was actually incapable of having proper control of the vehicle, the defence can challenge the reliability of police observational evidence — including body-worn video, the consistency of the observations recorded, and any alternative explanation for the driver’s presentation.
Alternative explanation for appearance or behaviour
Symptoms that can appear consistent with impairment — slurred speech, unsteady balance, or slow responses — can also result from an unrelated medical condition, injury, fatigue, or disability. Medical evidence establishing such an alternative explanation can directly undermine the prosecution’s case.
Defect in the police procedure
Where the observations relied upon were not properly recorded, the accused was not given a fair opportunity to respond, or any purported breath analysis or medical procedure was not properly conducted or explained, this can undermine the reliability of the evidence relied upon by the prosecution.
Necessity or duress
Where a person drove only because they were forced to by an immediate and genuine threat to safety, or to respond to a real emergency, the defence of necessity or duress may be available, though courts apply this narrowly and require the danger to have been immediate with no safer alternative.
What Happens Next
The Local Court process
- 01
DUI matters typically arise where police form an opinion of impairment based on observed driving and behaviour, often following a crash or an inability to complete a standard breath or drug test.
- 02
The matter is first listed for mention in the Local Court, where a plea of guilty or not guilty is entered.
- 03
If a not guilty plea is entered, the prosecution serves its brief of evidence, including police observations, any body-worn video, and medical or toxicology evidence, before the matter is listed for a defended hearing.
- 04
At a defended hearing, the prosecution must prove beyond reasonable doubt that the accused was actually incapable of having proper control of the vehicle due to the influence of alcohol or a drug, and the defence can challenge this evidence directly.
- 05
If a guilty plea is entered, or the charge is proven at hearing, the matter proceeds to sentencing, where the Magistrate considers the degree of impairment, any resulting harm, the accused’s driving history, and personal circumstances.
- 06
Once sentence is passed, any disqualification period begins immediately unless a stay is granted, and there is a right of appeal to the District Court against conviction or severity of sentence within strict time limits.
Frequently Asked Questions
Common questions
A PCA charge is based on a specific breath or blood alcohol reading, while a DUI charge under section 112 requires proof that the driver was actually impaired to the point of being incapable of proper control of the vehicle, based on observational and other evidence rather than a set reading.
DUI is typically charged where a reliable breath or blood reading is not available — for example, following a serious crash requiring immediate hospital treatment, where a test was validly refused for a medical reason, or where the impairing substance (such as a prescription medication) is not captured by the standard illicit drug testing regime.
Yes, DUI applies to impairment caused by any drug, including lawfully prescribed or over-the-counter medication, if it renders the driver incapable of having proper control of the vehicle, regardless of whether the medication was taken exactly as directed.
In some respects, yes, because there is no simple reading for the prosecution to rely on — they must instead prove actual impairment through observational and other evidence, which can be more open to challenge, though this also means the defence cannot point to a specific reading in response.
Yes, an automatic licence disqualification period applies on conviction, broadly comparable to that imposed for a serious PCA offence, though the Local Court retains some discretion over the length of the disqualification depending on the circumstances.
It is possible in appropriate cases, particularly for a first offence with a good driving history and strong supporting material, though courts generally treat DUI matters seriously given the nature of the offending, similar to how mid to high range PCA matters are approached.
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