Salt the gravel road. When clearing a very small stretch of road (a driveway, for example) loosen ice using a small quantity of commercial ice melt in the initial pass over the icy road. For longer stretches of road, use a commercial grade of road salt, which is dispersed from the back of a truck through a sifter or with a propeller system that dissipates the salt evenly. The salt or ice melt doesn't need to completely cover the gravel road to be effective; the salt reacts with the ice and causes it to melt and break apart.
Loosen the ice. Wait for the ice to start to melt after the salt has been applied. The timing will vary greatly based on several factors. A heavy amount of traffic on the road can cause the ice to break up faster. The air temperature will also play a role in the amount of time it takes for the ice to start to break apart once the salt has started to interact with the ice. Once the ice has loosened and is starting to melt, break apart the ice with a sledgehammer on small stretches of road. For larger stretches of road use heavy machinery, like a front-end loader or a skid-steer loader, to break the apart.
Remove the ice from the road once it has started to melt and it's been broken up into chunks. For short stretches, clear the ice by hand with a shovel. For longer stretches of road use a plow to clear all of the ice from the road. Attach the plow to small implements, like a lawn tractor or an all-terrain vehicle. For larger areas, clear the road with a commercial plow or hire a private contractor who has a plow mounted on the front of his truck.