The answer is, perhaps unsuprisingly, not clear. But while too few people know you don’t have to allow a vehicle search, the power differential during a traffic stop probably overrides abstract constitutional notions.

As the article says, be polite and minimize conversation. Police are used to the power differential and they are as comfortable with it as you are uncomfortable. They don’t want to hear about your constitutional law class or how you read an article in The Atlantic about traffic stops.