These are thin strips of sand that are repeatedly subjected to the most severe punishment the Atlantic Ocean can dish out. As dapster most correctly points out: Mother Nature is the real bruiser here, not ORV use.

I've been to Cape Hatteras many times and have never found these vehicles or their occupants to be a problem or a threat to the environment in any way shape or form. I mean if you want to split hairs, every time it rains in Zion the massive oil covered parking lots send waves of nasty petrochemical pollution directly into the nearby Virgin River. I'd be willing to bet this gelatinous gunk is way more voluminous than whatever gets dripped into the sands of Hatteras. I'm sure even more automotive filth gets washed into the Merced in Yosemite Valley and the side gorges of the Grand Canyon but so far I haven't heard anyone complain about what dripping oil pans are doing to the quality of the environment in these places.

The bottom line is that Cape Hatteras is a barrier strand that comes and goes with the seasons and Atlantic storm cycles and was primarily set aside as a place of recreation, with a sane regard for preserving the natural environment within reasonable bounds. If the Department of Interior proves too pigheaded about how to manage this recreation area reasonably I suggest that North Carolina take over and find a more suitable agency to run a most important asset to that state's tourist economy.