I go by the simpler ‘can you read his license plate’ rule. If you can read it, you’re too close.
LOL! I can't do that. I'd have to be holding the plate in my hand to read it!!
***If you can read it, youre too close.***
Ever get behind a gravel truck with the sign “Stay 200 feet back! Not responsible for gravel damage!”
But you have to get on their bumper to read the sign as t is so small.