Driving under the influence of cannabis: What applies?

It is estimated that about 100,000 patients in Germany are currently receiving cannabis (1). Thus medical cannabis is becoming more widespread in this country. The number of cannabis prescriptions is growing year by year (2). In addition, the German government has agreed in its coalition agreement on the controlled dispensing of cannabis for consumption purposes. It should therefore come as no surprise that cannabis for recreational use may be legalized in the coming years.

In this context, discussions about how cannabis use can affect everyday life are more relevant than ever. One of the most important questions here is how the use of cannabis affects road traffic.

How does the use of cannabis affect driving ability?

Nearly half of cannabis users (48%) in the United States believe that cannabis use does not impair driving ability, according to a survey. In contrast, only 14% of non-users believe that driving under the influence of cannabis is safe (3). So opinions are strongly divided – but how does it actually behave?

Theoretically, the psychoactive cannabinoid, the tetrahydrocannabinol (THC), can impair attention span and time and speed perception. In 2010, the American Journal of Addiction published a study that did not reach a clear conclusion as to whether or not cannabis has a significant negative effect on driving ability (4).

As part of another test in , participants were asked to consume alcohol or cannabis. Their driving behavior was then tested in a vehicle simulator. As a result, drivers who had consumed cannabis showed a more cautious driving style – for example, they drove more slowly and kept more distance to other vehicles, but also had a slower reaction time (5).

If cannabis is taken for medical-therapeutic reasons for a specific indication as prescribed and the titration phase has been completed, participation in road traffic is possible on a regular basis (6). The prerequisites are that the patient is in a stable condition, the use of the anesthetic does not negatively affect his general condition, and the patient critically questions his fitness to drive before starting to drive. In principle, therefore, the same requirements apply as for the discontinuation of an opioid for pain treatment (7).

Looking at the situation in the USA and analyzing the number of accidents in US states where cannabis is legal or prohibited, we find that the results are rather mixed. This is partly due to the difficulty of measuring driving under the influence of cannabis and the fact that not enough time has passed since legalization to collect statistically relevant data. Therefore, no causal relationship between legalization and an increase in traffic accidents can currently be established. (8). Most current research states that alcohol use is a greater threat to driving safety than cannabis use.

Legal situation in Germany

In Germany, driving under the influence of cannabis is regulated by several laws. The most important factors for the legal assessment are whether the ability to drive is negatively affected by cannabis use and whether this cannabis use can lead to the endangerment of other road users. In addition, depending on the case, it may be a misdemeanor or a felony, or – in medically justified exceptional cases – have no consequences. In individual cases, the driving license authority may request a specialist medical opinion and an MPU. In particular, this examines whether cannabis use is exclusively in accordance with the medical prescription. Drug-related criminal and traffic conspicuities and diseases relevant to driving suitability are also assessed (9).

Without inability to drive – fine according to § 24a Abs. 2 StVG

In principle, according to Section 24a (2) of the Road Traffic Act (StVG), it is not permitted to drive a vehicle at all while under the influence of cannabis (10). A violation is considered a misdemeanor. There is no equivalent to the per mille limit for cannabis. Evidence of cannabis consumption must be provided in the form of a blood sample. Provided that the driver’s ability to drive was not impaired while driving, driving under the influence of cannabis is an administrative offense that generally results in a fine of €500 and 2 points in the central traffic register in Flensburg for the first offense.

Impaired driving – offense according to § 316 StGB

The situation is different if the driver is unfit to drive, i.e. unable to drive the vehicle safely. Impaired driving is determined, for example, by conspicuous driving behavior.
“(1) Any person who drives a vehicle in traffic (sections 315 to 315e) while unable to drive the vehicle safely as a result of consuming alcoholic beverages or other intoxicating substances shall be punished by imprisonment for not more than one year or a fine if the offense is not punishable under section 315a or section 315c.”(11)
In this case, the driver commits a criminal offense that can be punished with a fine or even imprisonment for up to one year. In addition, according to § 69 StGB, the driver’s license is usually revoked. In the case of a first offense, the fine is approximately 1 month’s salary and the revocation of the driver’s license is for approximately 1 year.

Impaired driving + endangering road traffic – criminal offense according to § 315c StGB (German Criminal Code)

The consequences are particularly serious if the driver is not only unfit to drive due to cannabis consumption, but also endangers road traffic. This does not even require an accident, but the causing of a dangerous traffic situation, a so-called “near-accident”, is sufficient. In this case, the offender is liable to a fine or imprisonment of up to 5 years, plus the suspension of the driver’s license (12).

Driving with cannabis patients

Cannabis affects the human body differently than alcohol. THC can be present in the blood for up to 30 days after cannabis use (13). Patients who regularly use medical cannabis for therapeutic purposes will always exceed the test limit of 1 nanogram of THC per milliliter of blood.

But this will usually be inconsequential for cannabis patients according to § 24a para. 2 sentence 3:

“Sentence 1 does not apply if the substance results from the intended use of a drug prescribed for a specific case of illness.”

This means that if the driver, as a cannabis patient, consumed the cannabis based on a doctor’s prescription, he does not commit a misdemeanor.

If a cannabis patient wishes to apply for or renew a group 2 driver’s license (truck and bus: classes C, C1, CE, C1E, D, D1, DE, D1E as well as the driver’s license for passenger transport), an assessment according to Annex 5 is required according to §§ 11 and 48 of the Driver’s License Ordinance (FeV).

In general, the patients concerned are recommended to carry a copy of the last BtM prescription and a cannabis identification card filled out by the doctor in order to be able to prove the legal cannabis intake. Alternatively, the physician can also print out a certificate via his practice software that certifies that the patient in question is taking medicinal cannabis as a medicine.

In the context of the 60th Traffic Court Day, traffic experts have proposed to increase the permissible limit of one nanogram THC per milliliter of blood to 10 nanograms (14). But so far, the restrictions remain unchanged and continue to cause confusion among patients.

THC half-life in the body

The effect of cannabis occurs within a few minutes or hours, depending on the form of ingestion, and lasts between 2 and 8 hours (15). Depending on the type and regularity of ingestion, THC itself can be detected in the body for several days and its partly active degradation products even for several weeks after the last ingestion (13). The metabolization of drugs (degradation, technically known as metabolization) serves to prepare for excretion from the body. The speed of this process can be described by the half-life.

The elimination half-life of a substance, or half-life for short, is the time in which the concentration of a substance in the blood plasma has dropped to half of the original value. It is usually expressed in hours, or in minutes in the case of very rapidly excreted substances. After a second half-life has elapsed, a quarter of the original value is still found, and so on. It is assumed that after five half-lives, no drug is present in the blood or the drug is no longer detectable. The period of time during which THC is detectable by current methods depends, among other things, on the frequency of use: (15):

• for infrequent cannabis use, the average is 1-3 days;
• with regular use it can be 5-13 days (according to some studies even up to 30 days);

This means that an appropriate drug test may show a positive result even after several days in patients who use infrequently and even up to 30 days in patients who use regularly (13).

Conclusion

All in all, the topic of “driving and cannabis” is complex and must be considered from different perspectives. The legal regulations apply equally to all road users. However, the legal situation must be considered specifically with regard to the special features applicable to cannabis patients. In order to facilitate the lives of patients while maintaining the safety aspect, further more clearly defined legal requirements for the traffic participation of cannabis patients would be desirable. One example would be a higher limit value for the THC content in the blood.

References:

1. How Big Is Germany’s Medical Cannabis Market? [Internet]. [cited 2022 Nov 3]. Available from: https://www.forbes.com/sites/dariosabaghi/2021/08/09/how-big-is-germanys-medical-cannabis-market/?sh=5995442440f4

2. Gastautor. Auf diesen Gründen beruht die wachsende Anzahl an Cannabis-Patient:innen in Deutschland [Internet]. Krautinvest. 2022 [cited 2022 Nov 3]. Available from: https://krautinvest.de/auf-diesen-gruenden-beruht-die-wachsende-anzahl-an-cannabis-patientinnen-in-deutschland/

3. Holden D. Half Of Marijuana Users In The US Think They’re Fine To Drive Stoned [Internet]. BuzzFeed News. [cited 2022 Nov 3]. Available from: https://www.buzzfeednews.com/article/dominicholden/half-marijuana-users-us-safe-drive-while-high

4. Sewell RA, Poling J, Sofuoglu M. THE EFFECT OF CANNABIS COMPARED WITH ALCOHOL ON DRIVING. Am J Addict Am Acad Psychiatr Alcohol Addict. 2009;18(3):185–93.

5. Lenné MG, Dietze PM, Triggs TJ, Walmsley S, Murphy B, Redman JR. The effects of cannabis and alcohol on simulated arterial driving: Influences of driving experience and task demand. Accid Anal Prev. 2010 May 1;42(3):859–66.

6. Deutscher Bundestag. (2017, März 27). Drucksache 18/11701: Cannabismedizin und Straßenverkehr. Bundestag.de [Internet]. dejure.org. [cited 2022 Nov 3]. Available from: https://dejure.org/Drucksachen/Bundestag/BT-Drs._18/11485

7. Grotenhermen F, Häußermann K. Cannabis: Verordnungshilfe für Ärzte. 2., aktualisierte Edition. Stuttgart: Wissenschaftliche Verlagsgesellschaft; 2017.

8. Does Marijuana Legalization Increase Traffic Accidents? [Internet]. Reason Foundation. 2018 [cited 2022 Nov 3]. Available from: https://reason.org/policy-brief/does-marijuana-legalization-increase-traffic-accidents/

9. Müller-Vahl KR, Grotenhermen F. Cannabis und Cannabinoide: in der Medizin. 1. edition. MWV Medizinisch Wissenschaftliche Verlagsgesellschaft; 2019. 359 p.

10. § 24a StVG – Einzelnorm [Internet]. [cited 2022 Nov 3]. Available from: https://www.gesetze-im-internet.de/stvg/__24a.html

11. § 316 StGB – Einzelnorm [Internet]. [cited 2022 Nov 3]. Available from: https://www.gesetze-im-internet.de/stgb/__316.html

12. § 315c StGB – Einzelnorm [Internet]. [cited 2022 Nov 3]. Available from: https://www.gesetze-im-internet.de/stgb/__315c.html

13. Hadland SE, Levy S. OBJECTIVE TESTING – URINE AND OTHER DRUG TESTS. Child Adolesc Psychiatr Clin N Am. 2016 Jul;25(3):549–65.

14. Verkehrsgerichtstag in Goslar eröffnet [Internet]. Aktuell. [cited 2022 Nov 3]. Available from: https://rsw.beck.de/aktuell/daily/meldung/detail/verkehrsgerichtstag-eroeffnet-experten-diskutieren-aktuelle-themen

15. Sharma P, Murthy P, Bharath MMS. Chemistry, Metabolism, and Toxicology of Cannabis: Clinical Implications. Iran J Psychiatry. 2012;7(4):149–56.