Impairment of motivation and performance
In addition to driving under the influence of alcohol, the use of drugs such as cannabis is one of the major risks for road users. The problem is that the cannabis plant and its products contain the active ingredient tetrahydrocannabinol (THC), which has a psychoactive effect on the entire central nervous system and influences all human senses. “This should by no means be taken lightly,” says Dr. Thomas Wagner, traffic psychologist and head of the department of the officially recognized driver fitness assessment centers at DEKRA in Germany. “Users of cannabis products who drive a motor vehicle after ingesting the psychoactive substance endanger road safety on the one hand and also give rise to doubts about their fitness to drive on the other.” This applies even more so in cases of frequent or regular consumption of the supposed “lifestyle drug.” Cannabis use by road users is one of the topics highlighted in the 2022 DEKRA road safety report “Mobility of Young People.”
Alongside danger to health and reduced educational opportunities, cannabis use is also associated with an increased risk of road traffic accidents. “The extent of cannabis use is closely related to driving under the influence of substances and risky driving behavior,” indicates Dr. Thomas Wagner. For example, people are susceptible to this if they are looking for extreme experiences, have low self-control, or have a risk-friendly personality structure.
“The consequences of frequent, regular, and in particular of chronic cannabis use are multifaceted and may include components of both motivation and performance,” explains the DEKRA expert, referring, among other things, to his own research findings and studies that he compiled and evaluated together with Professor Dieter Müller of the Institute for Traffic Law and Traffic Behavior in Bad Dürrenberg, Germany, for a recent article on the subject of cannabis use by road users in “Zeitschrift für Verkehrssicherheit” (Journal for Road Safety).
“All the cognitive processes that are important for safe driving can be impaired,” Dr. Wagner goes on to say. That is, concentration, attention, reaction time, short-term and working memory, psychomotor skills, and perception of time and space. With regard to motivation, what is known as “amotivation syndrome” in long-term users has long been known about. This presents as apathy and loss of drive, motivation, and interest, and has a negative effect on the safe performance of driving tasks. The unsafe driving observed after cannabis use mainly involves lane keeping, driving speed regulation, and dealing with rules about right of way at traffic lights or intersections. Particularly among young drivers, conspicuous features such as slower driving, crossing the center line more frequently with increased abrupt steering wheel movements, and prolonged reaction times can be observed in connection with the use of cannabis.