the department of transportation has specific rules regarding the transportation of high pressure cylinders. they must be secured. they cannot be in an enclosed vehicle. they must be able to discharge directly in the atmosphere.( read in an open truck). check your federal and state regulations regarding transportation.
Is that for any quantity of tanks / compressed gas tank size or gas volume or for a quantity exceeding a specified threshold?
I secure my tanks anyway as I am quite aware of what might happen in a crash and as that is my main concern, but this requirement about "not in an enclosed vehicle, venting directly into open air" I would be violating... if it applies to me / my quantities that is.
That requirement may make a lot of sense for many gases, OTHER THAN AIR, (maybe including for oxygen) but if it indeed is a requirement for compressed air as well, then... "oh well, government"...
Jeez, really, is that enclosed scuba/rough camping converted utility trailer going to have to be an "outlaw"?
(If that constitutes derailment of thread, maybe it needs to be split of)