Abstract: A control system for enabling a conveyor cart or carts to run automatically along a running track. The or each cart comprises a sensor for detecting a guiding line extending along the running track and outputting detection data, and a steering control device operable in response to the detection data for steering the conveyor cart to follow the guiding line. The sensor is switchable for selectively detecting right and left edges of the guiding line. The right edge is detected for permitting the cart to run through a junction along a rightwardly curved branching or merging line. The left edge is detected for permitting the cart to run through a junction along a leftwardly curved branching or merging line.