Years ago, people built gravel driveways without first excavating the site. Then people learned that excavating to create a compacted site meant a firmer driveway with less chance of sinking and lower maintenance. Many people still build gravel driveways without excavating because of limited budgets. But instead of simply spreading gravel over the site, you can create a substantial driveway--without first excavating.
Walk over the entire driveway site to look for soft areas prone to water pooling. Wait until after a rain and walk over the area to look for puddles and spongy ground. Fill those soft and low areas with landscape rock.
Roll the tamper over the driveway site repeatedly until the ground ceases to compress when you walk on it.
Stack cinder blocks on the driveway perimeter to hold in the gravel. Stagger the blocks and create two layers for each row of blocks, placing a row or wall on each side of the driveway. Dry stack the blocks or make more permanent walls by applying wet mortar to the blocks.
Place a 3-inch layer of coarse gravel between the walls. Roll the tamper until the gravel stops giving under its weight. Apply a second 3-inch layer of coarse gravel and tamp the gravel down.
Apply a 3-inch layer of medium-sized gravel and tamp it down. Place a second layer of this medium-sized gravel; tamp it down.
Apply fine gravel to the remaining area until you fill the driveway to the total height of the cinder block walls. Apply the fine gravel in 3-inch layers and compact each layer before applying the next.