A conveyor for moving objects along a path is comprised of a plurality of spaced-apart rollers that define the path of the conveyor. The upper edges of the rollers are aligned to define the surface of the path. Two spaced-apart side rails having inward-facing surfaces define two side boundaries of the path. A barrier assembly is disposed within a gap in one of the side rails for facilitating loading and unloading of objects onto the conveyor from one side of the conveyor. The barrier assembly is comprised of a mounting plate mounted to the conveyor and a barrier pivotally mounted to the mounting plate. The barrier has a wall section generally aligned with the inward-facing surface on one of the side rails. The barrier is movable between a first position wherein the wall section is elevated relative to the upper edges of the roller and a second position wherein the wall section is disposed below the upper edge of the rollers.