How Do Police Use Roadside Drug Testing To Check For Cannabis Impairment?
A Guide To The Methods Used In Cannabis Roadside Testing, What Limits Of Detection Are There And What To Expect When Taking A Cannabis Roadside Test.
What Is A Roadside Cannabis Test?
A roadside cannabis test is a simple roadside drug testing procedure that is carried out by police to check if a driver is impaired through the recent use of cannabis. The roadside cannabis test is primarily designed to determine if a driver has consumed cannabis in the last few hours and is therefore likely to be impaired through its use.
Common Goals Of The Roadside Cannabis Test:
- To identify drivers who are impaired or unfit to drive due to the recent use of cannabis
- To establish recent cannabis use in relation to a driver’s fitness to drive
- To provide evidence to support the carrying out of further laboratory based testing
- To provide evidence to support prosecution in the event of a road traffic accident or road traffic violation
Which Method(s) Are Used To Conduct A Roadside Cannabis Test?
There are a number of different types of roadside cannabis testing being used internationally.
✔ Most commonly used type of roadside cannabis test
- Detects the presence of active THC molecules
- Produces results in minutes
- Most commonly used in the UK, EU, Australia and Canada
✔ Newer type of roadside cannabis test
- Designed to measure the level of THC in a person’s breath
- Currently in development/early adoption stage
✔ Other roadside cannabis tests
Field impairment tests are a series of physical and cognitive assessments that are conducted by police:
- Tests of balance and coordination
- Eye movement checks
- Reaction time tests
These roadside cannabis tests are intended to assess impairment, not the presence of chemicals in a person’s body.
How Does A Saliva Roadside Cannabis Test Work?
Saliva testing is the most common form of roadside cannabis testing.
Step-by-step:
- A swab or test stick is placed inside the driver’s mouth.
- Saliva is collected using the swab/test stick for 30-90 seconds.
- The test is then inserted into a portable analyzer/reader.
- The results of the test will be displayed on the screen of the analyzer/reader within 3-10 minutes.
The test detects Δ9-THC, which is the primary psychoactive cannabinoid found in cannabis. It does not detect CBD or any other cannabinoids.
THC Detection Time Frame For Roadside Cannabis Testing
Saliva-based roadside cannabis tests can only detect the presence of THC that has been consumed in the recent past.
Detection periods are dependent upon usage patterns.
- Occasional users: THC is typically detected in saliva for 6-24 hours after cannabis use
- Regular users: THC can be detected in saliva for up to 48 hours after cannabis use
- Daily heavy cannabis users: THC can be detected in saliva for 48-72 hours or more after cannabis use
Due to the fact that THC takes longer to clear from the mouth when smoked or vaped, roadside cannabis tests tend to look for recent exposure rather than long-term use.
What Will Happen If A Driver Fails A Roadside Cannabis Test?
If a driver fails a roadside cannabis test:
They will usually be taken to a police station
They will undergo additional testing (usually blood or more sophisticated saliva testing) to confirm the presence of THC
Many jurisdictions have a zero-tolerance approach to cannabis-impaired driving.
Possible outcomes:
- Penalties/fines
- Ban on driving
- Criminal charges
- Increased premiums for car insurance
- Points on their license
The extent of penalties will depend on local laws and the individual’s previous record.
Will Legal CBD Products Trigger A Positive Reading On A Roadside Cannabis Test?
CBD products that contain no THC will not produce a positive reading.
However:
- Some CBD products may contain small amounts of THC (typically between 0.2-0.3%)
- Products that are mislabeled or contain more THC than stated may also cause a positive reading
- While it is extremely unlikely, heavy CBD use may accumulate enough THC in some individuals’ bodies to produce a positive reading on a roadside cannabis test
It is recommended that drivers only purchase reliable lab-tested CBD products to minimize the risk of producing a false positive on a roadside cannabis test.
How Can Drivers Ensure They Remain Safe And Compliant With Cannabis Use?
Cannabis impairs people differently; as such, caution is advised.
Drivers should be aware of the following:
- Do not drive immediately after smoking/vaping cannabis
- Do not drive for an extended period of time after consuming cannabis (edibles require significantly longer waiting periods)
- Be aware that cannabis can affect cognitive function for several hours after use
- Only consume cannabis at home or in a safe environment where you intend to relax
- Purchase cannabis products from reputable suppliers with clearly labeled packaging
- Driving while under the influence of cannabis is hazardous and against the law.
Summary
As governments develop new policies to address increasing levels of cannabis use, roadside cannabis testing is becoming increasingly common worldwide. Familiarizing yourself with the process of roadside cannabis testing (saliva tests), the detection window for THC in saliva, and possible legal ramifications for failing a roadside cannabis test will assist you in exercising safe and responsible cannabis use practices and protect you and others on the road.
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