It takes very little off-road vehicle (ORV) traffic to make a significant impact on the dunes.

ORVs have more severe impacts than human trampling because they exert much higher stress on dune surfaces and vegetation. Horse-riding has similar levels of impact on dunes to ORVs.

Experiments by Anders and Leatherman (1987) on the dunes of Fire Island, NY, tested the effects of relatively low ORV use: 1 vehicle pass per week. By the end of one year, nearly all the vegetation in the impact zone was eliminated. Dune topography changed as a result of erosion in the impact zone.

Other studies show:

• The first few vehicle passes do the most damage.
• The number of blowouts in a dune environment increases when ORV use is present.
• More damage results when vehicles move straight up and down slopes instead of following contours or moving diagonally to contours.
• Vehicles may have the ecological side effect of bringing weed seeds with them.