A single-track railway.
Railroad that runs on a single rail; the automobiles can be balanced on it or suspended from it. It was invented 1882 to carry light loads, and when run by electricity was called a telpher.
The Wuppertal Schwebebahn, which has been running in Germany since 1901, is a suspension monorail, where the passenger automobiles hang from an arm fixed to a trolley that runs along the rail. Today most monorails are of the straddle type, where the passenger automobiles run on top of the rail. They are used to transport passengers between terminals at some airports; Japan has a monorail (1964) running from the city center to Hameda airport.