1. Roads and driveways are constructed of graded compacted sub base. They are then surfaced with crushed gravel to create a year-round driving surface. Angular rock in the road base is the most efficient, as it creates bridging by the stacking of the angular stone in the road pack. Round stone tends to roll our from under the weight of a tire just as any round object would roll across a flat surface. This is very noticeable on curves where all the stone works its way to the outer edge of the curve.

2. Some people finish their driveways with either concrete or asphalt. This is smooth but expensive and due to freeze/thaw conditions in Gunnison County, somewhat difficult and expensive to maintain over the long term.

Gunnison Conty standard specifications require six inches minimum depth and a minimum specification of CDOT class 6 (3/4" road base).

1. Multiply the length of the driveway by the width. As mandated by the County for fire protection, a sixteen foot width surfaced is required, not counting drainage ditches and catchment basins for required culverts.

2. Multiply all numbers in feet or decimal equivalent for depth. Example: 100 ft. long by 16 ft. wide by .5 ft. depth. To adjust for compacted depth, multiply by 1.25. This will give you the cubic feet.

3. Divide this number by 27 to convert to cubic yards.

4. Multiply cubic yards by 1.5 to get tonnage. Tonnage is how most gravel products are sold.