Might be an asphalt milling machine. These machines cut a layer of pavement off the surface of a road or parking lot to prepare for a layer of new asphalt. The asphalt removed is moved out the back, front, or side to a dump truck via a conveyor belt. The asphalt “millings” can be recycled into new paving material and used to make new roads. Some machines do the entire process in a single pass. They cut the surface layer off, heat and grind the material, add a bit of new tar, and lay a new layer of hot asphalt behind as they move along.