Cannabis and Driving: What the Law Actually Says in Spain and Europe
Share
Cannabis and Driving: What the Law Actually Says in Spain and Europe
In this guide
1. The Spanish legal framework: no fixed limit
Article 379.2 of the Spanish Criminal Code (Organic Law 10/1995) punishes driving "under the influence of toxic drugs, narcotics, psychotropic substances, or alcoholic beverages" with 3 to 6 months in prison (or a fine of 6 to 12 months plus 31 to 90 days of community service), plus loss of driving license for 1 to 4 years.
Unlike alcohol, which has an objective legal limit (0.25 mg/l in breath, 0.15 mg/l for novice drivers), Article 379.2 sets no numeric THC figure at all. For an offense to exist, prosecutors must prove real impairment of the driver's psychophysical abilities — combining police testimony with a toxicological expert report — a positive test alone is not enough. Royal Decree 1428/2003 (the General Traffic Regulations), in articles 27 and 28, regulates the checkpoint procedure, delegating the design of detection programs to the competent authority without setting a cutoff figure in the regulation itself either.
There is no official ng/ml cutoff threshold set by any DGT instruction or Spanish regulation for the saliva tests used at roadside checks. Internal DGT instructions (07/S-94 from 2007 and 08/S-102 from 2008) describe the procedure but do not set a figure. Any specific number circulating about "the Spanish threshold" depends on the calibration of the manufacturer's own device (Dräger, DrugWipe, etc.), not on any published Spanish law or regulation. If you see an exact figure presented somewhere as "the Spanish legal limit," be skeptical — no such fixed number exists in the BOE (Spain's official gazette).
2. Screening, confirmation, and legal consequences
The process, under Royal Legislative Decree 6/2015 (the consolidated Traffic, Motor Vehicle Circulation and Road Safety Act), has two clearly distinct stages:
- Screening (art. 14.3): a roadside saliva device gives a fast, indicative, non-forensic result
- Confirmation (art. 14.5): if the screening is positive, a second sample is taken and analyzed in a lab to confirm; the driver has the right to a contrast test, preferably blood-based, at their own expense if that also comes back positive
- Administrative route: detected and confirmed presence alone already constitutes a very serious offense (arts. 77 and 80, RDL 6/2015) — here, unlike the criminal route, there's no need to prove impaired driving
- Criminal route (art. 379.2 CP): requires, on top of presence, proof of real impairment of the driver's abilities; aggravating factors exist under arts. 380-381 CP for gross or reckless negligence, and refusing to take the test is itself a standalone offense (art. 383 CP)
The financial penalty and license-point figures that circulate in the media (around €1,000 and 6 points) are widely corroborated by specialized legal sources, but we haven't been able to verify their exact literal wording directly in the consolidated BOE text during this research — they're presented here as a generally accepted figure, not as a first-hand verified quote.
3. Presence vs. real impairment: the underlying scientific problem
From an educational standpoint, this is the most important part of the topic: THC doesn't behave like alcohol in the body, and that creates a genuine legal problem.
THC is a lipophilic molecule that accumulates in fat tissue. Johansson et al. (1989, European Journal of Clinical Pharmacology) documented a plasma half-life of 4.3 days in habitual users, reaching up to 12.6 days in some cases. Karschner et al. (2009, Addiction) found detectable THC in blood after 7 days of supervised abstinence in chronic users. This means a test can come back positive days after any real effect on driving ability has completely disappeared.
The official NHTSA report ("Marijuana-Impaired Driving: A Report to Congress," DOT HS 812 440, 2017) concludes in plain terms that the correlation between THC blood concentration and actual driving impairment is weak, with implications for whether it even makes sense to set numeric "per se" limits. Peak impairment happens in the first hour and a half after smoking, by which point blood THC has already fallen more than 80% from its peak. The EMCDDA/EUDA (report from the DRUID project, 2014) confirms that cannabis can indeed impair driving, but that the quantitative correlation with measured blood levels is much weaker than in the case of alcohol.
4. How other European countries regulate this
According to the EMCDDA, approaches vary considerably across EU countries: some use a "proven impairment" model (like Spain), others set a quantitative legal limit, and others combine both.
Germany
Since August 22, 2024 (reform of §24a StVG), the limit is 3.5 ng/ml of THC in blood serum for general drivers. Previously, a case-law value of 1 ng/ml applied, which still stands for novice drivers and those under 21.
United Kingdom
A legal limit of 2 micrograms per liter of THC in blood, in effect since March 2015 (Statutory Instrument 2014/2868).
Specialized Dutch legal sources cite a limit of 3 micrograms/liter for single use (or 1 ng/ml if combined with other substances), but we haven't been able to verify this figure directly against the original Dutch legal text during this research — it's presented here as a consistent secondary-source reference, not as a first-hand verified quote.
5. What the road-fatality data actually shows
The strongest and most recent data available comes from the 2025 Toxicology Report of Spain's National Institute of Toxicology and Forensic Sciences (INTCF), produced in collaboration with the DGT: out of 894 drivers who died in crashes and were autopsied, 72 (8.1%) tested positive for cannabis (up from 7% the previous year).
It's important to stress that this figure measures toxicological presence, not proof that cannabis caused the crash — the ambiguity described in section 3 explains exactly why. The European DRUID project (2006-2011) did calculate an adjusted statistical risk (odds ratio) of approximately 1.89 for a fatal crash associated with cannabis, with the combination of alcohol and cannabis multiplying that risk up to 15 times. That data point is already 15-20 years old, and we haven't found an equivalent, more recent pan-European update.
6. Frequently asked questions
No. Unlike alcohol, the Spanish Criminal Code sets no numeric THC limit. The administrative route penalizes detected presence alone; the criminal route additionally requires proof of real driving impairment.
In habitual users, studies have detected THC in blood up to 7 days after supervised abstinence — far longer than the actual window of driving impairment (roughly the first hour and a half after use).
A second sample is taken for confirmatory lab analysis. The driver has the right to a contrast test (preferably blood-based) at their own expense if that result is also positive.
No. According to the EMCDDA, different models coexist: Spain uses a "proven impairment" standard, while Germany (3.5 ng/ml in serum) or the UK (2 µg/L in blood) set specific numeric limits.
This article is for informational purposes only, covering traffic regulations and published scientific evidence. It does not constitute legal advice. For any real situation involving a roadside drug check, consult a lawyer specializing in traffic law. Beetle Print does not promote driving under the influence of cannabis or any other substance.
Grow knowledge, not just plants
Grinders, rolling papers, custom lighters, and accessories — everything around the experience, within the law.
Shop the Beetle Print catalog