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 (14, 15) 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 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 having at least an upward component has been exerted on the first body; wherein the force causes the first body to translate in an upward direction substantially perpendicular to a ground surface to produce the output; and wherein the output is configured to at least partially interrupt a transmission of drive to the ground engaging structure (14, 15) so as to stop or cut-out travelling of the lift vehicle along the ground surface at least in a direction towards the depression, in response to the force 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 (14, 15) 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 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 having at least an upward component has been exerted on the first body; wherein the force causes the first body to translate in an upward direction substantially perpendicular to a ground surface to produce the output; and wherein the output is configured to at least partially interrupt a transmission of drive to the ground engaging structure (14, 15) so as to stop or cut-out travelling of the lift vehicle along the ground surface at least in a direction towards the depression, in response to the force being exerted on the first body.