DRIVING is a privilege. If they establish (via dog perhaps) that I’m not carrying any contraband, and my driver’s license is valid, they can’t detain me until I’ve given them a complete “flight plan” and my life’s story.
That would be like a cop pulling me over for no reason at all: “where are you going? how long are you staying there? what is the address that you’re staying over the weekend? are you planning to speed tomorrow? have you run any red lights today?”
Not that I’m worried, but giving my itinerary to a stranger is actually borderline dangerous. They had the address on my license. Do I really want a stranger who knows my address to also know how long my apartment might be vacant?
This is the US, not a police state where I have to justify my actions to some power-hungry swine in a uniform.