From what I've gathered, police can ask for all kinds of things that they legally have no right to (searches, being let in, etc), but you can still ignorantly comply. They can even legally lie about shit to persuade you.
Have to disagree with "You haven't committed any crime" because these to my understanding occur during traffic violation. Not saying I agree with the practice but am saying cops are not pulling over perfectly legal drivers and saying "Sir/Ma'am please handover your cell phone".
An ambiguous crime. The limits are clearly posted, but enforcement is highly inconsistent. Driving the speed limit has probably become indicative of old age or an attempt to avoid police interaction. Try strictly driving the posted limit for a while and you will find it socially unacceptable. While most traffic stops are rightly due to excessive violation, some are an excuse to investigate. A stop for speeding makes a great cover should the motorist complain. If they were driving slower than the social norm, or even the cars around them, there is no hard evidence to support their case.
Right, and that's why you're not entitled to a jury trial for your speeding ticket. Speeding, running a light, etc., are not criminal offenses (except in extreme cases of reckless driving, where you may be on the hook for "reckless endangerment" or some such)
First sentence reads: "In the United States, most traffic laws are codified in a variety of state, county and municipal ordinances, with most minor violations classified as civil infractions."
They can't lie about them afterwards, but they can lie to you during interrogation. E.g. "your friend Joe already told us you did <whatever crime> so you might as well admit it." even if that's not true.
From what I've gathered, police can ask for all kinds of things that they legally have no right to (searches, being let in, etc), but you can still ignorantly comply. They can even legally lie about shit to persuade you.