by Martín Barriuso on 20/11/2017 | Consumption

Driving and Cannabis in Spain: The Criminalization Strategy (1/2)

Cannabis in Spain Is it dangerous to drive after using cannabis? In Spain, it is the harsh sanctions that pose a risk. Are these sanctions sufficiently grounded? Are things being done right? Are the drug tests even reliable? We explore this topic in the first instalment of a two part article.


Driving is becoming a dangerous activity for cannabis users in Spain. Despite the fact that saliva tests are still unreliable, the government has embarked on a strategy that criminalizes users. In the first part of this article, we analyse the present situation. Are saliva tests reliable? Is it dangerous to drive if we have used cannabis? What is actually being punished by the authorities?

Attempts to detect and prosecute people driving while under the influence of illegal drugs began in the 1980s in the United States. The European Union became interested in this issue in the 1990s. Ever since, Spain has been one of the most active countries in the development of this type of controls. Spain is one of the countries with the highest prevalence for the use of cannabis, cocaine, and other illegal drugs in the European Union, and also worldwide. Considering the high incidence of drunk driving and traffic accidents in Spain, as well as the prohibitionist attitude of governments in recent decades, it is not surprising that great efforts have been made to pursue people who consume illegal drugs and then drive.

Are drug tests for drivers Reliable?

The main obstacle that governments have had to face is twofold. On one hand is the lack of reliable methods to detect and measure the presence of drugs in the body. On the other, the lack of conclusive scientific information on how such drugs affect driving. In the studies carried out to compare the effects of alcohol and cannabis on driving, there is no doubt about the impairing effect of alcohol after the consumption of a certain dose or about the more disabling effect of combining alcohol and cannabis. However, the use of cannabis by itself does not seem to have an impairing effect, as shown by the results in simulators and real-life driving with users of the plant. Similar conclusions were obtained in the evidence review published in 2017 by the CDPC in Canada.

The effect of cannabis is linked to dose and experience

Experts believe that this apparent lack of impairment occurs because cannabis mostly affects highly automated functions, and those that require conscious control, such as complex driving actions, much less. When people become aware that they are under the effects of cannabis, they develop various strategies to reduce risk. The result is that their driving is little different from that of those who have not consumed any substance. It is also highlighted that the effect of cannabis is linked to dose and experience, and that long-time smokers are hardly affected. Still, the Spanish authorities insist that cannabis is always dangerous for driving, regardless of whether that claim lacks scientific support.

Unreliable drugs tests were used on drivers in Spain

A photo of a woman placing a mouth swab from a drug test to the roof of her mouth. In her right hand she holds the empty syringe.

In the last twenty years, the European Union has carried out various studies to determine whether the methods available to detect drugs are reliable or not. The first was the ROSITA project, which took place at the end of the 1990s and beginning of the 2000s. This study was followed by the ROSITA II project, which was carried out between 2005 and 2006. Both studies, coordinated by Spanish Professor Manuel López-Revadulla, revealed that the available methods at that time were not sufficiently reliable. Despite this, they began to be used in some Spanish regions.

The third European study was DRUID (Driving Under the Influence of Drugs, Alcohol, and Medicines), which started in 2006 and ended in 2010. Spanish institutions state that this report “recognizes the reliability of rapid detection devices,” as reflected in the 2010 Annual Report of the State Attorney General’s Office. However, as I reported in 2015 during the appearance of cannabis associations before the Drugs Commission of the Spanish parliament, the conclusions of DRUID actually state that “none of the tests has reached the levels of efficiency required in sensitivity, specificity, and accuracy for all the included separate tests.”

Many Drug Tests, But Few Reliable Results

Despite the lack of efficacy, in recent years there has been widespread use of drug detection saliva tests by different police forces. Tens of thousands of drivers are subjected to them every year. It is also mandatory to test all drivers involved in traffic accidents, whether they are unharmed, injured or killed. Nonetheless, it is not easy to draw conclusions from the data provided by the Traffic Department. To begin with, in the case of deceased drivers, an autopsy (in theory compulsory) is only performed on 60% of them. Without knowing why 40% of them are excluded, how can we actually trust the final data? In addition, the authorities often speak – probably intentionally – about the abundance of “positives for drugs and alcohol,” as though both tests could be equally assessed. In addition, as recognized by the DGT itself, the presence of psychoactive substances in the body is one thing but this being is the main cause of an accident is another. It should also be remembered that, being much more expensive than alcohol tests, drug tests are used more selectively and are, therefore, biased.

In 2016, the Civil Guard carried out 60.942 drug tests, of which 23.822 (39%) tested positive. On the other hand, 4.6 million Breathalyzer alcohol tests were used, of which 1.5% (68.852) yielded a positive result. These results do not include the tests carried out by autonomous police departments (Basque Country and Catalonia) or by local police. This striking difference between positive alcohol and drug results is not only maintained among the drivers involved in accidents (4.5% positive for alcohol versus 27% positive for other psychoactive substances). EDAP, a biannual study in which roadside tests are randomized, showed 12% of the drivers studied have used drugs other than alcohol, 3% tested positive for alcohol, and 1.5% tested positive for alcohol and other substances. If we take into account that the prevalence of alcohol consumption in Spain (close to 80%) is considerably higher than the sum of all illegal drugs and legal hypnosedatives combined, it is clear that something strange is happening.

Smoking Cannabis Is Forbidden, Even If It Does Not Affect You

Undoubtedly, the key to understanding this difference is the fact that the current Traffic Law prohibits driving “with alcohol levels above the established limit,” whereas for the rest of the drugs, their “presence in the body” is sufficient to keep you from driving. Obviously, the mere presence of drugs in the body is not the same as “being under the influence,” as the previous law stated. Faced with the accusation of punishing people who, only having remnants of cannabis or other substances in the body, do not represent a risk to driving, the government defends itself by saying that the tests (made by the German brand Dräger Drugtest 5000) are calibrated in a way that only detects consumption carried out between 3 and 6 hours prior to the taking of the sample.

From the outset, it is questionable to punish consumption 6 hours prior to the test, when it is known that the effects, even when cannabis is orally consumed, usually last much less. In fact, the NHTSA (the equivalent of the DGT in the US) considers the effects of cannabis on driving as lasting around three hours. But everything indicates that this detection period is actually much longer, as evidenced by the large number of people who turn to associations and specialized lawyers saying they have been fined one or two days after they have consumed. There are also many positives among passive smokers, which shows that the amount of cannabis needed to be sanctioned is minimal.

An absolutely unreliable test

The person responsible for the evaluation of the tests, Manuel López-Rivadulla, says that, “a positive result means that the person has consumed between three and nine hours prior to testing the sample, and that being very generous.” Although he also admits that there are regular users of cannabis for whom instead of “nine hours, it can take as much as twelve hours,” that is, four times more than the effect lasts. Looking at the manufacturer’s estimates, it turns out that detection period would be between a few minutes and 24 hours. However, even this seems not to be true, because when the Energy Control association – one of the main risk-reduction organizations in Spain – wrote to Dräger to ask how long it is necessary to be without cannabis to test negative, they answered that they did not know.  The uncertainty about the reliability of the test is therefore absolute.

This interest in downplaying the imprecision of the Drugtest 5000 is perfectly understandable from the manufacturer’s perspective; ultimately, they want to sell the product. But what is the interest of the supposedly independent evaluators? Probably an economic one, since the Forensic Toxicology Service of the University of Santiago, which López-Rivadulla runs, obtained the contract – of almost €1.5 million per year – to perform the complementary blood laboratory tests. Of course, if they had said, as the European Union did, that the test is not accurate enough, they would have been left without a contract, so this obvious conflict of interest should make us doubt the objectivity of their claims.

Thanks to Claudio Vidal, Héctor Brotons, Nuria Calzada y Rafael Agulló, for their help writing this article.

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