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.
Aérotrain
Though similar to a maglev design, which levitates a train car over a complex electromagnetic track to eliminate all resistance other than aerodynamic drag, the Aérotrain — also a "train without wheels" — rode on an air cushion over a simple reinforced concrete track or "guideway" and could travel at unprecedented speed, without the further technical complexity and expense of the maglev track. In many respects, the entire concept resembled a product of the aircraft rather than rail industry.