Escalator with a series of steps connected to at least one drive chain, driven by a motor mechanism, travelling via an advanced track and a return track placed alongside, there being transition zones between two levels, said tracks respectively comprising a main set of guides and at least one set of additional guides for moving a movable step, via the bearing thereof, parallel to a non-movable step, so that they are positioned at the same height, creating a widened continuous platform which can accommodate a person with reduced mobility.