Our 10 lot subdivision HOA must regrade and crown the first 300 ft. entrance portion of the unpaved roads. This section is very steep making erosion a chronic issue. Built originally 35 years ago with "rotten rock" surface and refurbished most recently 4 years ago with "Acadia Mix", both materials have benefits and downsides.  Are there any recommendations for the best surface material in this situation, - rotten rock, Acadia mix, minus 1 crushed ledge, reclaimed asphalt, other?