Avoid driving for 24 hours after cannabis consumption

The German Motoring Association (ADAC) conducted tests and recommends that occasional cannabis users should avoid driving for at least 24 hours after consumption. According to ADAC's findings, presented on Monday, it is unsafe to drive before this period.

In Germany, the legal limit for THC in blood serum for drivers is three-and-a-half nanograms per millilitre. For novice drivers, the limit is one nanogram per millilitre. In Luxembourg, the THC limit for all drivers is set at one nanogram per millilitre of blood.

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ADAC's study assessed the abilities of three cannabis users at intervals of one hour, four hours, and 20 hours after consumption. Blood samples were taken each time to measure THC levels. Results showed that compared to their sober state, participants performed worse in both driving and cognitive tests.

Test subjects displayed signs of absent-mindedness, such as failing to adjust the seat or side mirrors, struggling to orient themselves on the road, parking incorrectly, and driving dangerously or too fast. Cognitive tests revealed impairments in memory and concentration.

Accident risk clearly increases

When THC concentration in the blood reaches between 7 and 12 nanograms per millilitre, it is significantly above the legal limit. Four hours after consuming cannabis, THC levels dropped to three-and-a-half nanograms per millilitre, but this did not ensure safe driving. The ADAC found that the test subjects' self-assessment and performance in driving and cognitive tests were still inadequate for safe driving.

It was only 20 hours after consumption that the test subjects showed improvement in their driving abilities, as confirmed by blood tests and expert evaluations. Consequently, the ADAC strongly recommends that individuals refrain from driving for at least 24 hours after consuming cannabis to minimise accident risk.