A standard urine or blood test cannot definitively determine whether an individual was stoned while driving – or the night before, or three weeks ago, for that matter. Police are often forced to resort to field sobriety tests to demonstrate that a driver is high, essentially leaving it up to officer discretion as to whether or not a person is too intoxicated to be behind the wheel.
As more U.S. states and other countries move to legalize marijuana, researchers have been working on ways to improve drug testing technology. In Colorado, law enforcement officials have been conducting a three-year program in which they are testing a number of similar devices.
That same device is now likely to become part of Canadian law enforcement’s arsenal later this year. An independent committee of toxicologists and traffic safety experts has since evaluated a number of these saliva testing tools and recommended the Draeger model, giving Canadian Attorney General Jody Wilson-Raybould 30 days to approve the device.
Once approved, police will be able to order these devices and begin training in how to use them. One remaining issue to be considered is that these devices do not seem to function well in extremely cold temperatures, of which Canada has no shortage.
Although the new device may provide more accurate results than a standard field sobriety test, the science regarding drug impairment testing is less established, and hence can lead to more controversy. Any driver who tests positive for drugs on the saliva-testing machine can be brought in to a police station for further testing, including blood tests. C-46 legalized “Per se” limits for drug blood levels, which allows police to criminally charge any driver who exceeds a certain THC level, even if they are driving perfectly safely.
Current scientific evidence does not conclusively connect specific THC blood levels with increased traffic accident risks and therefore any “Per se” blood limit imposed by the government is somewhat arbitrary. An experienced cannabis user with high tolerance may be able to drive more safely than a first-time toker, even if they have the same levels of THC in their blood.