Abstract: A switcher track apparatus comprising four switch units having precisely supported turntables at the intersections of the rails of two tracks, with switch sections of the track on the turntables movable into alternate switching positions in alignment with the two tracks and with magnet assemblies for establishing and releasably holding precise alignment. A dolly or sled for riding on the tracks has four wheel assemblies at its corners each comprising two rows of four roller wheels in a V-shaped arrangement for engagement with curved rail surfaces. The wheel assemblies are carried on sprockets that are tied to a driver sprocket on a T-bar for operation in unison.