https://www.techdirt.com/articles/20191125/15400643456/oregon-supreme-court-shuts-down-pretextual-traffic-stops-says-cops-cant-ask-questions-unrelated-to-violation.shtml

The Supreme Court's Rodriguez decision took a lot of fishing line away from law enforcement officers. Thousands of traffic statutes are violated every day. (Or not broken, in some cases.) All an officer needed to do was follow someone around until they violated one and then turn the traffic stop into a Q&A session with an eye on obtaining consent to search drivers, passengers, and vehicles.

The Supreme Court said pretextual stops are fine, but once the objective has been achieved (citation or warning given), the stop is over. No further questions. No calling for a drug dog. Nothing. Some officers took this to mean they could violate the Fourth Amendment as long as they did it quickly enough. Some courts allowed them to get away with speedy Constitutional violations. But, more often than not, courts interpreting the Supreme Court decision have read it as saying there's no extending a stop without reasonable suspicion to do so. There's some gray area, but not as much as officers had hoped.