That arch is off of Poison Spider trail in Moab and over looks the Colorado river. Here is a picture of my buddies walking across the arch in the other direction. It is pretty steep but you have crazy traction on that slick rock.
haven't been there in a couple years but I'm pretty sure that is a big no no. No vehicles past this point painted on the rock about40 yards back. Not 100% as its been a while but worth bring up.