Colonization of the Moon
If multiple bases were established on the lunar surface, they could be linked together by permanent railway systems. Both conventional and magnetic levitation (Maglev) systems have been proposed for the transport lines. Mag-Lev systems are particularly attractive as there is no atmosphere on the surface to slow down the train, so the vehicles could achieve velocities comparable to aircraft on the Earth. One significant difference with lunar trains, however, is that the cars would need to be individually sealed and possess their own life support systems.
Maglev
Maglev (derived from "magnetic levitation") is a system of train transportation that uses two sets of magnets, one set to repel and push the train up off the track, then another set to move the 'floating train' ahead at great speed taking advantage of the lack of friction. Along certain "medium range" routes (usually 200–400 miles) Maglev can compete favorably with high-speed rail and airplanes.