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Published: 5 April 2023

Can you drive a few days after taking drugs?

Have you ever wondered how long drugs stay in the human body? We will cover this question and the criminal charges related to drugs and driving in this article.

If a person in NSW mixes drugs and driving, the door is open to a plethora of criminal offences, such as:

  1. Driving with illicit drug present in oral fluid, blood and urine
  2. Driving under the influence of drugs
  3. Driving with morphine present in oral fluid, blood and urine
  4. Arrested person or driver involved in an accident refusing to provide samples
  5. Altering the amount of drug present before testing

Whether a person is convicted of an offence depends on the circumstances of the case and if any defences are applicable.

First, let’s dive into the research.


The Alcohol and Drug Foundation has provided rough timelines for the duration for drugs to remain in the human body.

Cannabis depends on the usage, for infrequent users it will remain in the salvia for 12 hours. However, for frequent users the salvia will typically test positivity up for 30 hours. Users can expect their urine to test positive for between 10 and 30 days.

There is often public debate about this finding, an example of which can be found here.

Within the “party drugs”, MDMA remains the longest compared to cocaine and ketamine.

  • MDMA: 2 days for saliva and 3 to 4 days for urine.
  • Cocaine & Ketamine: less than 24 hours for saliva and 2 to 3 days for urine

Methamphetamine will remain in salvia for up to 2 days and in urine for 2 to 5 days. Interestingly, benzodiazepines will last significantly longer in urine (up to 2 weeks) compared to in salvia (less than 24 hours).

As with all scientific research, the results will depend on the reliability of the experiments and data. It is not advised to strictly follow these timelines as a multitude of factors will influence the length a drug will remain in a person’s system. Commonly the following factors can have the largest impact:

  1. Potency
  2. Tolerance
  3. Metabolism
  4. Existence of medical conditions

You can access the Alcohol and Drug Foundation’s research findings here.


The criminal offence of Driving with illicit drug present is a “strict liability” offence, meaning that a lack intention to drive with drugs present cannot be used as a defence. The prosecution must prove beyond a reasonable doubt that the driver:

  1. Operated a motor vehicle or
  2. Attempted to put the vehicle in motion or
  3. Occupied the passenger seat if instructing a L Plate driver and
  4. An illicit drug present in their oral fluid, blood or urine.

There are limited defences available if the elements are proven, these include:

  1. Necessity
  2. Duress
  3. Honest and reasonable mistake of fact
  4. Morphine – medical consumption

Morphine is a unique case. Medicines and painkillers commonly contain morphine, and due to this the law has allowed for a special exception for driving with morphine present if consumed for medical purposes only. However, this consumption must be in line with the prescription, purchased from a pharmacy and taken in accordance with the manufacturer’s instructions.


The police are empowered to test drivers on NSW roads for the presence of drugs via Mobile Drug Tests (MDTs). The usual situation a driver will face is as follows:

  1. Pulled over by police patrol car
  2. Asked for licence
  3. Roadside Breath Test for alcohol
  4. Mobile Drug Test

MDTs are the initial salvia tests, which if positive will mean the driver will be taken to a police drug bus or police station for a secondary test. If the secondary sample is positive, the driver will likely be suspended from driving for a period of 24 hours. The secondary sample is sent to a laboratory for further testing, and the result may take months to return. If the secondary sample is positive under laboratory conditions, the driver may be charged with Driving with illicit drug present.

Once the secondary sample is returned as positive, the police officer is empowered to either issue a penalty notice or a court attendance notice for a first-time offender. However, repeat offenders must receive a court attendance notice.


Following the penalty notice, first time offenders will be required to pay a $603 fine and will be suspended for three months. If an offender is issued with a court attendance notice, the following penalties apply if a conviction is recorded:

First offence:

  • Maximum fine $2,200
  • Disqualification period between 3 and 6 months

Secondary and subsequent offences:

  • Maximum fine $3,300
  • Disqualification period between 6 and 12 months


What happens if the police officer believes a driver is affected by drugs? The police will consider the criminal charge of Driving under the influence of drugs.

This will require the police officer to record their observations of the driver and issue the driver with a court attendance notice. The prosecution must prove beyond reasonable doubt that the driver:

  1. Operated a motor vehicle or
  2. Attempted to put the vehicle in motion or
  3. Occupied the passenger seat if instructing a L Plate driver and
  4. Was affected by an illicit drug.


The maximum penalties for this charge are serious:

  • First offence
    • $3,300 fine
    • 18 months imprisonment
    • 12 months to 3 years disqualification period
  • Second offence
    • $5500 fine
    • 2 years imprisonment
    • 2 years to 5 years disqualification period

Due to the nature of this criminal offence, the defences are limited and will depend on the facts of each case.

At Morrisons we are specialist criminal and traffic lawyers based in Wollongong and the Southern Highlands. If you require advice or representation, you can book an appointment with one of our expert criminal lawyers.

Contact us today

We are the only private law firm in the Illawarra, Southern Highlands and South Coast regions with two lawyers recognised as Accredited Specialists in Criminal Law by the NSW Law Society.