A driver interface assembly (10) is provided comprising a controller element (15) mounted to a body (16) which forms an integral part of an armrest (11) associated with a driver's seat (12). The body is rotatable with respect to the armrest between two positions: (a) an operating position, in which the controller element is exposed for operation thereof, and (b) a stowed position in which the controller element is concealed from use. The body remains substantially within the profile of the armrest when in both the operating position and the stowed position. The volume occupied by the armrest (11) can therefore be exploited to mount and stow a controller element (15). This is particularly advantageous in a working environment where space is at a premium.