The stat is not for 'impaired' drivers. Due to the testing procedure used, which lacks accuracy in the time domain, the stat is: 'has used cannabis this month.'

The stat is not for 'impaired' drivers. Due to the testing procedure used, which lacks accuracy in the time domain, the stat is: 'has used cannabis this month.' More people are able to use cannabis when it is legal, so this number would be expected to increase.