Good point. Forgot about the freewheeling, no brakes. So use to setting the brakes in the tractor & the spring loaded brakes on the trailer are engaged as soon as you remove the air pressure. Nothing like caged brakes! Kind of strange, about 8 years ago OSHA dropped the requirement of using chocks. It is the responsibility of the person working the trailer, NOT THE DRIVER who is responsible for securing the trailer to the dock doors. Just about all LTL & most TL trucking companies donít use wheel chocks, but 99 % of their customers require you set the chocks. Go figure?