A method inspects a conveyor (10) having opposing sides (34, 35) and a length. The conveyor includes an endless belt (16) and a plurality of roller structures (24) disposed in spaced relation along at least a portion of the length of the conveyor and under a top flight (17) of the belt for supporting the belt while material is being conveyed on the belt. Each roller structure includes at least one roller (12, 12′) constructed and arranged to rotate about an axis as the belt is conveyed with the material. The method orients an unmanned vehicle (22), having sensor structure (28) thereon, at one side of the conveyor, and causes the vehicle to travel along the portion of the length of the conveyor while the sensor structure obtains data regarding a state of at least a portion of the belt and of rollers of the plurality of roller structures while the conveyor is operating.