The information described here refers to current research results and the current law (July 2023).
Does cannabis have any influence on driving behaviour at all?
The simple answer is « Yes! » … In certain doses, cannabis is thought to affect the ability to drive. Cannabis can, among other things, affect visual perception (e.g. Light sensitivity – this is particularly dangerous at night because of the oncoming traffic with their lights on) and psychomotor skills, which in turn can influence driving behaviour.
A number of other factors influence whether a certain dose of cannabis is associated with impaired driving ability. These include the form of consumption (if cannabis is smoked, inhaled or eaten), whether cannabis alone or with other substances (e.g. alcohol) and, above all, the question of whether the user rarely or regularly consumes cannabis.
What does the law say about cannabis and road traffic?
In Luxembourg, active road users are allowed 1 ng THC/ml blood, which is close to « zero tolerance ». A cannabis intoxication lasts a few hours, but this limit can be reached even several days/weeks/months after the last use.
Depending on the amount and frequency of consumption of CBD cannabis, a THC level in the blood of 1ng/ml or more can already be achieved, which is not allowed under Luxembourg law. Although CBD products do not cause high.
If you are tested positive for cannabis in traffic, you run the risk of losing your driver’s license. Even if you are no longer under a state of intoxication and only THC degradation products are detected in the blood or urine.
Does the insurance pay in case of an accident caused under the influence of Cannabis?
No! If you cause an accident under the influence of cannabis, whether you are at fault for the accident or not, the insurance company may refuse to pay the costs.
How long is cannabis detectable?
Although after consumption the proportion of THC decreases after a few hours below the concentration required for the psychoactive effect, cannabis can be detected days, weeks or even months after the last consumption.
How long cannabis can be detected varies greatly from person to person and depends largely on the amount and duration of consumption. The following information is to be seen as guidelines:
- in saliva: cannabis can be detected by means of a saliva test for up to several hours. In the event of a positive result, a blood and urine sample is taken from the person.
- in the blood: several hours with occasional consumption and several days with regular consumption.
- In the urine: 3–30 days, sometimes up to 3 months, depending on the duration and intensitiy of consumption.
- in the hair: The longer the hair, the longer the regular consumption can be detected. In the case of 12 cm long hair, for example, conclusions can be drawn about the consumption of one year.
Summary: why you should not drive under the influence of cannabis:
If cannabis use is proven, you can expect fines and a driver’s license withdrawal.
In the event of an accident, the insurance no longer applies.
Under the influence of almost any psychoactive substance, your cognition is impaired. This is irresponsible to others and to yourself. In road traffic you need to stay sober.
There are many alternatives if you have used cannabis to get from A to B (public transport (free in Luxembourg), night bus, taxi, etc.).
If you have any other questions about cannabis, please contact our FroNo hotline:
- By phone: (+352) 49 7777 55, from Monday to Friday from 9am to 1pm.
- By e‑mail: email hidden; JavaScript is required
- By WhatsApp: (+352) 691 497 755
Here is a selection of additional Cannabis Know How Cards!
If you notice that a person is not well after having consumed legal or illegal drugs, act responsibly and look after that person. If in doubt, phone the emergency number and administer first aid.