Abstract: An accumulating conveyor system for shuttling conveyor trucks along a conveyor track from a drop off point at the end of a first conveyor drive to a point at the beginning of a second conveyor drive. The accumulating conveyor system includes a drive track which extends parallel along the conveyor track. A plurality of tractors ride along the drive track and selectively couple with a truck at the drop-off point, then tow the truck along the conveyor track to the pick-up point of the second conveyor drive where the tractor uncouples from the truck. A return track extends parallel along the drive track for enabling return of the tractors from the pick-up point to the drop-off point. A switch mechanism transfers the trucks from the drive track to the return track and then back to the drive track.