More natural-looking surfaces are more acceptable to riders. It is less expensive to install surface treatments when a trail is new than to repair and treat a used trail. Runoff water was collected at the bottoms of various hills to study the effectiveness of various surface treatments. Dramatic differences were found between treated and untreated areas. Sunny trails also experience less erosion than more shaded ones.
Downhills erode less than uphills.
The surface grade was measured across trails over a period of time to determine the amount of soil loss. Better riders generally cause less erosion because of less skidding and wheelspin. It is desireable to stop trail widening. At Southern Kettle Moraine silt loam soils seem the most wear-resistant due to the binding effect of the clay portion of the soil. Sandy soils, while not very erodable, provide such a loose riding surface that they contribute to trail widening as trail users avoid the loose surface.