To pile on to glenns towing comments, I pick up ratchet straps along the highway all the time, where they've rubbed in two and fallen off. Especially where they go over a sheet metal edge, they'll wear through in a heartbeat, especially if they're attached to the rollback bed and the suspension compresses going down the road, It would be much better to hook them on the truck chassis instead so they don't loosen as the suspension flexes.
