> No person shall drive a motor vehicle at such a slow speed as to impede the normal and reasonable movement of traffic, except when reduced speed is necessary for safe operation. [1]
Versus California:
> No person shall drive upon a highway at such a slow speed as to impede or block the normal and reasonable movement of traffic unless the reduced speed is necessary for safe operation, because of a grade, _or in compliance with law_. [2] (underscore emphasis mine)
It’s part of the Uniform Vehicle Code but each state has its quirks in how they adopt it since theres no federal mandate.
My apologies though, this seems way less common than I thought. As far as I can tell Georgia and Oregon are the only two states left that don’t have that compliance exception.
On the other hand “in compliance with law” is it’s own barrel of monkeys because it doesn’t specify priority.
[1] https://law.justia.com/codes/georgia/title-40/chapter-6/arti...
[2] https://leginfo.legislature.ca.gov/faces/codes_displaySectio...