Tow conveyors uses towline to provide power to wheeled carriers such as trucks, dollies, or carts that move along the floor. It is used for fixed-path travel of carriers (each of which has variable path capabilities when disengaged from the towline). In this towline can be located either overhead, flush with the floor, or in the floor. Here Selector-pin or pusher-dog arrangements can be used to allow automatic switching (power or spur lines). They are generally used when long distance and high frequency moves are required. A tow conveyor includes at least one carrier. Connected to the front and rear of the carrier are rod members extending forwardly downward and rearwardly downward respectively and pivotally movable in horizontal and vertical directions. Running assemblies free to move on guide rails are connected to the lower ends of the rod members respectively so as to be pivotally movable in horizontal and vertical directions. A trolley driven on endless rails has pivoted thereto a pusher engage able with the engaging dog and tilting dogs to be pivotally forced down by the tilting plate on the rear running assembly of a preceding carrier to thereby tilt the pusher through a link when the carrier approaches the preceding carrier.