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.
List of maglev train proposals
San Juan – Caguas: A maglev project has been proposed linking Tren Urbano's Cupey Station in San Juan with two proposed stations to be built in the city of Caguas, south of San Juan. The maglev line would run along Highway PR-52 connecting both cities. According to American Maglev Technology (AMT), who is the company in charge of the construction of this train, the cost of this project is approximately US$380 million.