Most railway tracks are tilted at curves to offset centrifugal forces felt by passengers as they move through those curves. When higher-speed trains use tracks designed for slower trains, however, the greater centrifugal forces at curves can cause passenger comfort and safety issues. Since building new tracks for faster trains is often impractical, tilting trains have been developed.

A tilting train has an internal mechanism which allows the train body or passenger section to lean into turns. This allows the sideways centrifugal force to be experienced in a more comfortable and safe downward manner.

Tilting trains either have a passive mechanism which responds to outward forces, or an active mechanism which is controlled by an onboard computer.

The first tilting trains were deployed in Europe in the 1950s. These early tilters used passive tilting. The first active tilter was the Advanced Passenger Train deployed in Britain in the early 1980s.