But here is what I don't get. Let's say a Drunk person downloads this app, and finds out that their route from the party to home goes through a checkpoint. Aren't they now more likely to just stay wherever they are? Without the app, the person would risk it and drive drunk all the way to the checkpoint, endangering everyone along the way.
Alternative option for the drunk person using the app is to take an alternative route. Since I presume most checkpoints are on populated routes, then even if the person goes around they will be on a less populated road than their intended route.
I'm just not sure how this app being used makes me as a sober driver any less safe. It would appear to make me more safe. I'm open to suggestions to the contrary, as long as they have some logic behind them