A buffer storage device (100) for an overhead conveyor system (10) having individually conveyable transport units (40), with a closed conveying path that includes a buffer section (117) along which transport units are conveyable downstream, a feed section (104) for feeding transport units to a feed point (102) of the buffer section, a discharge section (105) for discharging transport units from a discharge point (103) of the buffer section, and one or more additional bypass sections (113) which in each case connect a starting point along the buffer section to a destination point along the buffer section.