RubberTyred

Rubbertyred refers to a system in which rail vehicles gain propulsion primarily from rubber tires that run on a hard surface, with additional guidance provided by steel wheels or guide wheels on a separate track or guide rail. This configuration is used in some urban rail transit, notably rubber-tired metros, to provide traction and stability on urban grade changes and varying loads.

In typical rubbertyred systems, the vehicle is equipped with multiple large-diameter rubber tires that bear the weight and deliver drive torque. The tires run on a smooth ground plane, while conventional steel wheels or small steel rollers guide the vehicle along a separate guide path, which may be a central rail or a dedicated groove. Some designs use a combination of two tire sets for propulsion and a separate steel wheelset for steering and guidance. This arrangement allows for strong contact with the surface and reliable guidance via the rail or guide wheels.

Advantages of rubbertyred systems include improved traction, especially on steep grades, and generally quieter, smoother operation compared with traditional steel-wheel rail systems. They can also provide better acceleration and braking performance in dense urban environments. Disadvantages include higher tire wear and maintenance costs, greater susceptibility to debris on the road surface, and potentially higher energy consumption.

Rubbertyred technology has been adopted in several city systems around the world, with notable examples in Paris and Montreal. It remains one of several approaches within urban rail to balance ride quality, performance, and infrastructure considerations.