At a mandatory alcohol screening checkpoint, like at current selective breath-testing checkpoints, the practice is that as cars come along, they're waved in. That doesn't change at all. The difference is that instead of the officer coming up to the car and asking you for your vehicle ownership, your licence, and your insurance to try to detect the telltale odour of alcohol, they simply present you with the machine and say, “Blow.” So in many ways, it may well be faster than our current selective breath-testing procedure.
On September 18th, 2017. See this statement in context.