A segmented, belt-driven conveyor system for use in clean environments. High speed, high density, collision free throughput of work piece carriers is enabled through belt-driven conveyor segments each having co-rotating drive wheels. The drive wheels have a cylindrical profile. Predefined acceleration/deceleration profiles may be employed by a motor controller to affect optimal changes in work piece carrier speed across the respective drive segment. A peripheral groove is formed in idler wheels within a drive segment. A soft, pliant ring of material is disposed in the groove. The ring protrudes slightly beyond the crown of each wheel. The drive belt then remains in contact with the ring when unloaded and the wheel peripheral surface itself when loaded through compression of the pliant ring. By reducing intermittent contact between the belt and the wheels, particulation is reduced.