A lift vehicle comprising: A chassis ; wherein the chassis is supported by a first ground engaging structure proximate a first end of the chassis and a second ground engaging structure proximate a second end of the chassis ; wherein the chassis comprises a propulsion system for moving the lift vehicle via the first and second ground engaging structure and the lift vehicle comprises a platform mounted to the chassis and moveable between a raised position and a lowered position with respect to the chassis ; and a stability system for inhibiting tipping of the lift vehicle , the stability system comprising: a first body mounted to the chassis and configured to extend at least partially between the first ground engaging structure and the second ground engaging structure ; wherein the first body is moveable relative to the chassis between a deployed position in which the first body enhances the stability of the lift vehicle if the lift vehicle is driven into a depression (D) when the platform is in the raised position, and a stowed position when the platform is in the lowered position; characterized in that when the first body is in the deployed position, the stability system is arranged to produce an output indicating that a force (F) having at least an upward component has been exerted on the first body ; wherein the force (F) causes the first body to translate in an upward direction substantially perpendicular to a ground surface (G) to produce the output; and wherein the output is configured to at least partially interrupt a transmission of drive to the ground engaging structure so as to stop or cut-out travelling of the lift vehicle along the ground surface (G) at least in a direction towards the depression (D), in response to the force (F) being exerted on the first body . A chassis ; wherein the chassis is supported by a first ground engaging structure proximate a first end of the chassis and a second ground engaging structure proximate a second end of the chassis ; wherein the chassis comprises a propulsion system for moving the lift vehicle via the first and second ground engaging structure and the lift vehicle comprises a platform mounted to the chassis and moveable between a raised position and a lowered position with respect to the chassis ; and a first body mounted to the chassis and configured to extend at least partially between the first ground engaging structure and the second ground engaging structure ; wherein the first body is moveable relative to the chassis between a deployed position in which the first body enhances the stability of the lift vehicle if the lift vehicle is driven into a depression (D) when the platform is in the raised position, and a stowed position when the platform is in the lowered position; characterized in that when the first body is in the deployed position, the stability system is arranged to produce an output indicating that a force (F) having at least an upward component has been exerted on the first body ; wherein the force (F) causes the first body to translate in an upward direction substantially perpendicular to a ground surface (G) to produce the output; and wherein the output is configured to at least partially interrupt a transmission of drive to the ground engaging structure so as to stop or cut-out travelling of the lift vehicle along the ground surface (G) at least in a direction towards the depression (D), in response to the force (F) being exerted on the first body . <EOS>