Abstract: In a sortation conveyor system, a main conveyor is provided with an improved transport surface that permits the substantially frictionless movement of articles in a transverse direction relative to the forward motion of the conveyor. The transport surface includes a plurality of twin slats alternating with transverse roller assemblies which support a plurality of anti-friction rollers. Both the slats and the roller assemblies are carried by side chains. The anti-friction rollers are mounted such that the upper radial surface of each extends above the twin slats for supporting the articles being conveyed. Diverters held captive on the slats slide across the surface and direct articles in a transverse direction while supported on the anti-friction rollers, this permitting substantially frictionless movement of articles to a lateral takeaway conveyor.