A monorail is a metro or railroad with a track consisting of a single rail, as opposed to the traditional track with two parallel rails. There are two systems: in the suspended monorail the train is located under the track, suspended from above; in the straddle-beam monorail the train straddles the 'rail', which is called straddle-beam (i.e. it covers it also on the sides).
Monorail systems have been built in many locations around the world, many of them on elevated tracks through crowded areas that would otherwise require the construction of expensive underground lines or have the disadvantages of surface lines.
Japan has employed monorails for rapid transit in six cities, including Tokyo and Osaka. Jacksonville, Florida, Vancouver, British Columbia and Kuala Lumpur, Malaysia also have a rapid-transit monorail. Monorails have also proved useful as people-movers in Walt Disney World (Orlando, Florida) and the Tampa, Florida and Newark, New Jersey airports. The installation in Walt Disney World is the busiest monorail in the world. A short monorail was built in Seattle for the Century 21 Exposition in 1962 and its expansion begins construction in 2004. Las Vegas, Nevada is currently constructing a monorail to run along the famous Las Vegas Strip to ease that city's traffic headaches. It is scheduled for completion in late 2004.
It should be noted that all these systems have switches. Some early monorail systems, notably the suspended monorail of Wuppertal (Germany), dating from 1901 and still in operation, have a design that makes it difficult to switch from one line to another. This limitation still figures in discussions of monorail. However, both for the suspended and for the straddle-beam type monorail the problem has been surmounted.
See also: Public transport