A sorting conveyor system (46) comprising a main conveyor line (48) intersected by cross conveyors (18) having roller-top conveyor belts (20). The roller-top conveyor belts, which can be driven bidirectionally perpendicular to the conveying direction of the main conveyor line, have article-supporting belt rollers (22) that can rotate freely in the main conveying direction (14). Articles (38) fed from the main conveying line onto the cross conveyor can be sorted to the left or the right by the conveyor belt. Articles destined for sorting downstream pass over the stopped roller-top conveyor belt atop the freely rotatable belt rollers and back onto the main conveyor line. A booster (40), such as a motorized roller (40), between the main conveyor line and the cross conveyor applies a force in the main conveying direction against articles destined to cross the cross conveyor.