Saliva drug tests: self-testing before driving

It's a question that rightly plagues many drug users. You can read a lot about it on the Internet, especially on forums. There's some serious information out there, but there are also a lot of far-fetched theories.

For example, it has been widely reported that, while saliva drug tests can indeed reveal that a person has taken drugs, they can in no way tell whether that person is still under the influence of those drugs. In other words, they make no difference between people whose effects are still active and those whose effects have completely faded.

Technically, this is true.
Except that this type of argument cannot be used to contest the validity or effectiveness of these saliva tests when used by the police.

Why is that? Logic!
The saliva tests currently used at the roadside detect cannabis use between 3 and 6 hours after the last joint. Yet the psychotropic effect of cannabis lasts around 3 to 6 hours, depending on the individual and the amount of cannabis consumed. There is therefore an almost perfect correlation between the time it takes to detect cannabis and the duration of its effects.

Therefore, we can logically say that a person who tests positive on a saliva test is still under the effects of cannabis, and thus represents a danger not only to themselves, but also to all road users.

So how can you be sure that you'll be able to get back behind the wheel without putting yourself in danger and risking committing an offence?

Three solutions:

• Stop taking drugs.
  
  
• Wait at least 48 to 72 hours before driving again. The effect of the drugs will have worn off, and you will no longer represent a danger to yourself or others.
  
  
• People who absolutely need to get back in their car as soon as possible will take a saliva test to make sure it's negative. If it's positive, they'll have to postpone their departure accordingly, or look for a driver or a car-sharing solution.