Could be the loss of someone's life...
At the box someone didn't use their parking brake, truck popped out of gear and almost killed a couple of people.
It's worth it to have one, wether it is required or not.
I understand that completely. I wouldn't let my truck sit on the tranny I'd chock it and put on as flat of ground as I could find, I'm just askin cuz I don't have a parking brake, I plan to try to fix it but I'm not sure I'll be able to