Limit and fines
Anyone who drives a motor vehicle with 3.5 ng/ml of THC or more in their blood serum commits an administrative offence (§ 24a para. 1a StVG). Anyone who also drinks alcohol risks more (§ 24a para. 2a StVG). The limit is low: according to the Federal Ministry of Transport’s expert group, this level can already impair the ability to drive safely, and the risk is comparable to a blood alcohol level of 0.2 per mille (0.02%). Impairment can also occur below it.
Fines and driving bans for THC at the wheel
Probationary period and under 21
During the probationary period and before your 21st birthday, the rule at the wheel is: no THC at all. You may neither use cannabis while driving nor set off under the influence of THC (§ 24c StVG). Prescribed medicines are exempt.
Driving when unfit is a criminal offence
Regardless of the limit: anyone who drives a vehicle although they cannot drive safely because of intoxicating substances is punishable by up to one year in prison or a fine, even if they acted negligently (§ 316 StGB).
Driving licence and MPU
If facts point to dependence, the driving licence authority requires a medical report. It orders a medical-psychological assessment (MPU) if there are signs of misuse, after repeated offences under the influence of cannabis, or after the driving licence has been revoked for this reason (§ 13a FeV).
Feeling sober is not enough
In one study, many people felt fit to drive again even though their performance was still clearly worse. Impairment can remain once the noticeable effects have worn off, and the risk of accidents is increased. So the rule is: if you have used cannabis, you do not drive until enough time has passed.
How long that is cannot be said precisely for cannabis, because the amount, THC content and usage habits vary widely. The professional societies for traffic psychology and traffic medicine recommend these waiting times as a minimum:
How long should you wait after using cannabis?
- At least 12 hoursoccasional use, a moderate amount smoked or vaporised
- At least 24 hoursTHC content unknown or a larger amount
- More than 24 hourseaten or drunk
- Usually 3 to 5 daysregular use on several days a week, moderate amounts
- Several weeksdaily or several times a day
Occasional means there are several days between two days of use. A moderate amount is no more than 25 mg of THC. This cannot be predicted precisely for cannabis. If you are unsure, leave the car at home.
What tests detect
At roadside checks, saliva tests are used as a preliminary test; the blood sample is what counts. Other tests, for example of urine or hair, find breakdown products long after the high has passed.
What each test shows
Salivause in the last few hours
Preliminary test at roadside checks. What then counts for the fine is the blood sample.
BloodTHC for a few hours, longer with frequent use
Decisive for the limit. With regular use, THC is stored in fatty tissue and gradually released again.
Urinebreakdown products for about 30 days
Even longer with regular use.
Hairmonths
Shows use far back in time, not the current high.
usual periodwith frequent use
Where use is prohibited
The Consumer Cannabis Act (KCanG) prohibits use in the immediate presence of minors, in schools, at children’s playgrounds, in children’s and youth facilities, at public sports facilities and in cultivation associations, in each case also within sight of them; this ends at a distance of more than 100 metres from the entrance. In pedestrian zones, use is prohibited between 7 am and 8 pm (§ 5 KCanG).
Where use is prohibited
In the presence of minorsAnywhere, as soon as children or young people are in the immediate vicinity.
Schoolsand within sight of them
Children’s playgroundsand within sight of them
Children’s and youth facilitiesand within sight of them
Public sports facilitiesand within sight of them
Cultivation associationsand within sight of them
Pedestrian zonesfrom 7 am to 8 pm
“Within sight” ends at a distance of more than 100 metres from the entrance. In North Rhine-Westphalia (NRW), using cannabis in a no-consumption zone costs €50 to €500, and in the presence of minors €300 to €1,000. Our map of no-consumption zones shows where this applies in Dortmund.
Possession and storage
From the age of 18, you may possess up to 25 grams away from home, and up to 50 grams and three living plants at home (§ 3 KCanG). Possessing more is an administrative offence or a criminal offence. At home, cannabis must be protected from access by others, especially children and young people; a breach can cost up to €30,000 (§§ 10, 36 KCanG).
No passing on to others
Cannabis from a cultivation association must not be passed on to others, not even to adults (§ 19 para. 4 KCanG). Unauthorised passing on is a criminal offence; adults over 21 who pass cannabis on to minors as a rule face three months to five years in prison (§ 34 KCanG).
Possession and passing on at a glance
- Under 18ProhibitedPossession, acquisition and cultivation
- 18 and over, away from homeUp to 25 gramsMore is an administrative offence or a criminal offence.
- 18 and over, at homeUp to 50 grams and 3 plantsKept safe from children and young people.
- Passing onProhibited to anyone elseIncluding to adults, including as a gift.
Fines in NRW
Under the state’s catalogue of fines, using cannabis in the presence of minors costs €300 to €1,000, and using it in no-consumption zones €50 to €500. These rates apply to a first intentional offence and double for a repeat offence within three years.
Fines in NRW
What the evaluation shows so far
The Act requires an independent scientific evaluation (§ 43 KCanG). It is being carried out by the EKOCAN research consortium: the Centre for Interdisciplinary Addiction Research at the University Medical Center Hamburg-Eppendorf, University Hospital Düsseldorf and the Institute of Criminology at the University of Tübingen. The consortium presented its first interim report in September 2025, around 18 months after the Act came into force, and the second by 1 April 2026. It examines child and youth protection, health protection and cannabis-related crime. The results are preliminary; the evaluation runs until April 2028.
The evaluation after two years
What has emerged so far
- Young peopleUse stable or slightly declining. The risks tend to be taken more seriously than before.
- AdultsThe increase seen for about 15 years is continuing. The data show no jump caused by the Act.
- Road trafficNo significant change in driving under the influence of cannabis or in the numbers of people injured and killed.
- ChildrenPoisonings were extremely rare before and still are.
- Law enforcement60 to 80% fewer cannabis offences, mainly because use and possession of small amounts are no longer prosecuted.
Where problems remain
- Early interventionYoung people end up in programmes such as FreD less often, because the justice system hardly refers anyone there any more.
- Addiction counsellingYoung adults use it less often, even though more of them are being treated because of cannabis.
- High-potency productsSupply is growing, above all medical cannabis from online pharmacies. This can put more strain on mental health.
- Illicit marketStill active. In 2025, customs seized more than four times as much as in the previous year.
- Cultivation associationsOnly 366 licensed by October 2025. At most 3.5% of people who use cannabis were able to obtain it from them.
Sources
- Road Traffic Act (StVG), §§ 24a and 24c
- Catalogue of Fines Ordinance (BKatV), annex
- Criminal Code (StGB), § 316
- Driving Licence Ordinance (FeV), § 13a
- drugcom.de (BIÖG, 2022): people who use cannabis overestimate their fitness to drive after smoking
- German Road Safety Council (DVR): drugs
- BMDV (2024): recommendations of the interdisciplinary expert working group on the THC limit in road traffic
- DGVP and DGVM (2024): recommended waiting time after using cannabis before taking part in road traffic
- drugcom.de (BIÖG, 2018): why cannabis can be detected for so long
- drugcom.de (BIÖG): drug glossary, entry on drug tests
- BIÖG (2025): cannabis information for parents
- Consumer Cannabis Act (KCanG), §§ 2, 3, 5, 9, 10, 19, 34, 36
- MAGS NRW: rules and fines for cannabis control
- EKOCAN (2025): evaluation of the Consumer Cannabis Act, 1st interim report
- EKOCAN (2026): evaluation of the Consumer Cannabis Act, 2nd interim report