In one aspect of the invention, a milling machine for milling a paved surface comprises milling tools connected to an underside of a body of the machine and also a depth probe comprising a base end opposite a distal end. The probe is connected to a front end of the machine through a probe base disposed proximate the base end. A monitor is adapted to detect a distance between the distal end of the probe and an outer surface of the base. The distal end of the probe is adapted to extend away from the outer surface of the base and penetrate into a paved surface.