Monorails are trains that run on a one-rail track, often elevated above the ground level. The single-rail construction distinguishes monorails from any other elevated railway, although light rails and elevated cable car systems are often wrongly classified as monorails. There are several well-known monorail systems throughout the world, with two of the most recognizable serving as transportation lines for Disneyland in Anaheim, California, and Disney World in Florida.
The technology and concept behind modern monorails has existed since the early 19th century. One of the first monorails opened in 1825 in Hertfordshire, England. Although developed as a freight train, this early monorail soon began carrying people as well. In the United States, one of the earliest monorail systems was built in Pennsylvania and opened in 1878, after its capabilities were demonstrated at an 1876 Exposition. Many early monorails featured wooden tracks and cars, although some, such as the Listowel and Ballybunion line of Ireland, used steel.
In the 20th century, monorail construction reached new heights. Although most monorail cars straddle the single rail, some were designed to be suspended below the rail instead. Both the Skyway monorail in Texas and Ueno Zoo monorail system of Japan used suspended, rather than straddling, cars. By the mid-1950s, most monorails were also constructed of steel and concrete, considered to be safer by far than the original wooden designs.
Seeking to stay at the forefront of technology, Walt Disney began implementation of a monorail system at his Southern California park in the late 1950s. Opened in 1959 as part of a large expansion of the futuristic Tomorrowland section of Disneyland, the Alweg monorail featured a sleek, modern design that almost looked more like a rocket ship than a train. The Disneyland monorail remains an important feature of the park, with trains frequently updated to remain consistent with new technology and safety standards.
Modern monorails are now available on every continent except Antarctica. Many work as small-scale transportation devices for parks, zoos, and large shopping districts. Yet some, like the Schwebebahn line in Germany, which also happens to be the oldest running monorail in the world, serve as commuter trains. Considered to be extremely safe, only four fatalities were recorded on monorails in the 20th century. These single-rail trains can also be an environmentally friendly form of mass transportation; in 2007, the famous Disneyland monorails were retrofitted to burn less-polluting biodiesel instead of ordinary gas.