The present invention relates to a wheeled vehicle and a method of operation thereof. The invention is particularly suitable for use in relation to mobility aids for the disabled. The wheeled vehicle includes a frame, a first wheel assembly including first and second wheels having parallel and spaced apart axes of rotation, wherein the first and second wheels are adapted to pivot about a first pivot axis relative to the frame, and a second wheel assembly including a third wheel adapted to pivot about a second pivot axis relative to the frame. Some embodiments are adapted to provide a wheeled vehicle that is capable for ascending and/or descending a step. Some embodiments are adapted to facilitate pivoting of the first and second wheel assemblies using a single actuator.
