A ridable miniature railway (US: 'riding railroad' or grand scale railroad) is a ground-level, large scale model railway that hauls passengers using locomotives that are models of full-sized railway locomotives (powered by diesel or petrol engines, live steam engines or electric motors).
Typically miniature railways have a rail track gauge between 5 in (127 mm) and 18 in (457 mm), though both larger and smaller gauges are used.
These large model railroads are most often seen in urban parks or in commercial settings, such as amusement park rides.
The major distinction between a miniature railway and a narrow gauge railway is that miniature lines use models of full-sized prototypes. There are miniature railways that run on gauges as wide as the 2 ft 6 in (762 mm) gauge on the defunct Viewliner Train of Tomorrow, or as wide as the 2 ft (610 mm) gauge on the operating Wicksteed Park Railway. There are also narrow gauge railways running on extremely narrow track as small as 15 in (381 mm) gauge or less, for example the Rudyard Lake Steam Railway, Perrygrove Railway and the Eaton Hall Railway. These are known as minimum gauge railways.