Blazing, it's as safe as I can make it -- very stout components. But I am bothered by the idea of a severe rear end collision busting out the back wall of the trailer, which would almost certainly cause the gas can and its "secure" platform to fall. Not likely to happen, but not a pretty scenario.
The fact that it is a gas can would not be visible to a following driver -- the whole thing is up pretty high, and the can is recessed inside the milk crate. A trucker might be able to see into the crate to tell what is inside.
