Monorails are single-rail systems often found in airport transfers and medium-capacity metros. Monorails differ from trams and light rail systems by always being separated from other traffic and pedestrians, and they do not use pantographs.

A railway that uses a single rail for support and guidance is called a Monorail. There are two primary types: Straddle monorails, where the train sits on top of the rail (like the Walt Disney World Monorail), and Suspended monorails, where the train hangs beneath the rail (like the Wuppertal Suspension Railway in Germany). Most modern monorails in 2026 use rubber tires that run on a concrete beam, which makes them quieter and capable of handling steeper grades than traditional steel-on-steel trains. While they are often associated with theme parks, cities like São Paulo, Chongqing, and Tokyo use them for high-capacity urban transit. A high-value technical distinction is that while "Maglev" trains also use a single guideway, they are often categorized separately because they "levitate" rather than make physical contact with a rail. Monorails are favored in dense cities because their elevated structure takes up very little "footprint" on the ground, allowing them to be built directly over existing highways or through tight urban corridors.