In the United States, the Firearm Owners Protection Act has a "Safe Passage" provision that allows you transport firearms through states where you do not have a permit as long as the firearms are not readily accessible. Does this or a similar law apply to things that aren't guns?
For example, California only allows "safe and sane" fireworks, or those that do not leave the ground or explode. However, nearly all types of consumer fireworks are legal in Nevada. Police in California are known to set up checkpoints near the border so they could confiscate unapproved fireworks that enter the state.
If someone bringing in fireworks from Nevada crosses a checkpoint in California and gets pulled over, but says they are transporting the fireworks to Washington (another state that allows nearly all fireworks), then would they be free to go?
I asked this question on a now-defunct fireworks forum years ago, and the answer was a resounding "yes." However, no one who replied to me actually provided a source or cited specific laws. I did some Googling and could not find any mention of a "peaceable journey" law that does not apply specifically to guns.
