drug driving saliva tests may not be accurate, page-2

Let's remember that if someone tests positive on a saliva test, the police officer doesn't usher them from the car and execute them on the roadside.

It's a 'first pass' test.

Never having driven drunk, or tested as such, I'm not speaking from experience, but I would imagine that the person would be subjected to a drug test (blood/urine/whatever) if they were to be tested positive by saliva.