A conveyor system and corresponding method for article volume sharing between conveyor lines includes an overflow handler in operational connection with the alignment conveyor of each conveyor line. The overflow handler receives articles positioned outside of the alignment region of the alignment conveyor and transports the articles to an alignment conveyor positioned within an adjacent conveyor line. Volume sharing between a plurality of conveyor lines increases conveyor system throughput, particularly when one or more of the conveyor lines experiences a high volume of article flow. The conveyor system includes a deflector assembly capable of deflecting articles away from the alignment region of the alignment conveyor and towards the overflow handler, and subsequently to an adjacent conveyor line, when the sortation conveyor is jammed or offline during the performance of maintenance.