I would find it quite surprising if the police implemented mandatory alcohol screening in a manner inconsistent with what every other country does, or what the vast majority of other countries do. That is, every driver passing along, unless there is a lineup, is waved in, and that's not dissimilar to what happens now. Now in a sobriety checkpoint, when you're pulled in currently, it's up to the officers to use their own subjective judgment in terms of whether to assess your potential sobriety and to decide whether or not there are reasonable grounds to suspect you have alcohol or drugs in your body. That's the individual, subjective judgment of the officer. Under mandatory alcohol screening, the officer has no individual discretion. Best practice is you're pulled in, and if you're stopped, you're asked for a breath sample.
On September 18th, 2017. See this statement in context.