Why does the USA do ‘sobriety field tests’ for suspected DUIs?

Question

When other countries (notably Europe) use roadside ‘Breathalyzer’ test machines? It seems a high-functioning drunk could get away with DUI in the US, when they wouldn’t in France or the UK?

In: Other

Answer 1

For the same reason cops in the UK might do a “Field impairment test”. Cops in both countries can do a breathalyzer, but drivers could be impaired for non alcohol reasons.