A crushed stone surface is a common lower cost method of surfacing for trails with low use, in rural areas, in environmentally sensitive areas to minimize run-off, or other reasons as locally specified. The cost model assumes a 3 inch stone surface depth.
How the Default Unit Cost was Determined
A cost range of $240-359/cubic yard was derived from estimates provided by The Rails to Trails Conservancy. A cost of $37/cubic yard was derived from a 2000 Iowa DOT report cost. This value is consistent with other paving values whereas the Rails to Trails numbers appear to be consistent with full trail construction rather than just the cost of surfacing.