Snowblowers on Gravel: Why Single-Stage Is Wrong
The surface changes the machine
A single-stage snowblower clears by letting its rubber-edged auger touch the ground and fling snow and whatever is under it out of the chute. On a paved drive that is the point. On gravel, it digs up stones and throws them at windows, cars and people, and it chews its own paddles. A two-stage machine rides on adjustable skid shoes with the auger held above the surface, so it can be set to leave the top layer of gravel alone.
How many towns it affects
For a two car driveway, switching from paved to gravel moves 912 towns to two-stage. The largest of them are Chicago, IL (39 in), Columbus, OH (28 in), Indianapolis, IN (26 in), Denver, CO (49 in). In 706 towns the answer stays a shovel either way, because there is too little snow to justify any machine.
Gravel without buying a two-stage machine
Where the snow is light, a shovel or a push plow with the blade lifted a little does the job. Some people leave the first inch or two packed down early in the winter so it freezes into a base above the stones. Whatever clears the drive, set the skid shoes high and clear the first pass slowly. For the machine itself, see single-stage or two-stage, and for how often ten-inch storms land in your town, why storm depth matters more than snowfall.