Skyline Drive is a 11.4 mile lightly trafficked out and back trail located near Corona, California that features a cave and is rated as moderate.
I've looked it up in dictionary, "traffick" means "deal or trade in something illegal", I don't know how it relate to the trail. And what does "out and back" mean here? Does it mean starting a hiking then walking back over the same route?
Thanks for your help！