The Department of Transportation allowed trucking lobbyists to review an unpublished report recommending a safety device that could save lives by preventing pedestrians and cyclists from getting crushed under large trucks.
Why make it more difficult to get around when you could just let people learn not to go under enormous mountains of steel? Honestly there are reasons why adding more stuff to trailers will make things more difficult. There's lots of places I've delivered to where I'd have gotten stuck, and all that stuff adds more weight which means less efficient transport and more emissions.