Asphalt Driveway Planning
An asphalt driveway is a layered system: compacted subgrade, crushed stone base, and hot-mix asphalt surface. The base layer is critical -- 6 inches of compacted crushed stone (minimum) provides the structural support. Without a proper base, the asphalt will crack and fail within a few years.
Standard residential asphalt thickness is 3 inches for passenger vehicles. If trucks, RVs, or heavy trailers will use the driveway, go to 4 inches. The asphalt must be placed and compacted while hot (275-325°F) -- this is not a DIY material. A paving contractor uses a paving machine and roller to achieve proper compaction and smoothness.
Best time to pave: late spring through early fall when temperatures are consistently above 50°F. Asphalt placed in cold weather doesn't compact properly and fails prematurely.