American vs European race transporters

I've observed that each American race transporter I've seen makes use of these liftgates which are held horizontal by chains and may't actually pivot up and down until the gate is being closed and an additional set of chains is used, whereas Euro vans appear to universally use hydraulic gates that may be tilted and transfer at will utilizing hydraulic pistons and a distant.

Does anybody know why it's like that? Is there some kind of regulation that stops American vans from utilizing hydraulic elevate gates? The European resolution appears far more handy to make use of, however I've by no means seen a single American one use the identical expertise, so it makes me surprise if it's a matter of legality slightly than comfort or custom.