A single-drum roller has just one roller, on the front, with special tires mounted on the back. It’s smaller than a double-drum roller, which has a second roller in place of tires. A single-drum roller is lighter and has more traction than its double-drum counterpart, but it may not roll over some terrain because it’s heavier in the front. A double-drum roller has the advantage of being able to compact areas in front and to the rear of the machine at the same time.