[HoMiPa]

It is law in New Hampshire as well. Although I am always surprised by the number of trailers I see without the chains crossed, or even NO chains!

As for the cradle, yes, that's what it is for, but the cradle is what limits the amount of sway in a trailer that has come detached - and the sway will be significant as the TV tries to stop. Digging into the pavement would be the least of your worries compared to the sway. Those videos you see of trailers flipping on the highway? Yeah, that sort of sway....