First and foremost they must have reasonable suspicion to effect a traffic stop - the only reason to stop is based on that reasonable suspicion - anything after that is on the driver - cooperation goes a long way- feel free to allow a search if your a subject and not a citizen- it’s your right to refuse a search, you can refuse a field sobriety test - with consequences- you can refuse a search — it’s best to make the officer tell you why they pulled you over — never admit to what they pulled you over for - it’s their job to tell you - which gives you their reasonable suspicion .. they won’t pull you over for no reason… you’ve given them a reason — they will look out for themselves as soon as they stop. They are watching you before they step out of their car.. behave ..
