The National Highway Traffic Safety Administration report to Congress [0] seems pretty clear in terms of the art of the science and the impairment observed from national data.

I would avoid incarceration of anyone from a test like this without significant and clear data that there is an actual problem we need to resolve. There are plenty of well proven driving problems we could focus on correcting.

[0] https://www.nhtsa.gov/sites/nhtsa.dot.gov/files/documents/81...