A device for immobilizing a wheeled vehicle, comprising: • a first chock member configured to be arranged on a first side of, in front of or behind, a wheel of a said vehicle in a state of use of the device, • a second chock member configured to be arranged on a second opposite side of said wheel in said state of use, and • an arrangement (5, 11a, 11b, 11c) interconnecting said first and second chock members (6a, 6b) and controllable to cause relative movement of these towards and from each other so as to move the chock members (6a, 6b) between a locking position in which the first and second chock members (6a, 6b) are wedged between the wheel and a ground on which the wheel rests on said first and second sides of the wheel, respectively, so as to prevent the wheel from moving, and a releasing position in which at least one of the chock members (6a, 6b) is moved away from and located at a distance to the wheel so as to allow the wheel to move, characterized in that the device further comprises: • means (7, 8) configured to rest on said ground in said state of use of the device and hold the chock members (6a, 6b) at a distance above the ground in a rest position and to allow the chock members (6a, 6b) to move to the ground while storing potential energy by these means (7, 8) when the chock members (6a, 6b) are moved towards each other by control of said arrangement (5, 11a, 11b, 11c) and by that pushed against the wheel and guided along this towards the ground for obtaining said locking position of the chock members (6a, 6b), and that these means (7, 8) are configured to automatically return to said rest position by releasing the potential energy stored when the chock members (6a, 6b) are moved away from each other and from said locking position. • a first chock member configured to be arranged on a first side of, in front of or behind, a wheel of a said vehicle in a state of use of the device, • a second chock member configured to be arranged on a second opposite side of said wheel in said state of use, and • an arrangement (5, 11a, 11b, 11c) interconnecting said first and second chock members (6a, 6b) and controllable to cause relative movement of these towards and from each other so as to move the chock members (6a, 6b) between a locking position in which the first and second chock members (6a, 6b) are wedged between the wheel and a ground on which the wheel rests on said first and second sides of the wheel, respectively, so as to prevent the wheel from moving, and a releasing position in which at least one of the chock members (6a, 6b) is moved away from and located at a distance to the wheel so as to allow the wheel to move, • means (7, 8) configured to rest on said ground in said state of use of the device and hold the chock members (6a, 6b) at a distance above the ground in a rest position and to allow the chock members (6a, 6b) to move to the ground while storing potential energy by these means (7, 8) when the chock members (6a, 6b) are moved towards each other by control of said arrangement (5, 11a, 11b, 11c) and by that pushed against the wheel and guided along this towards the ground for obtaining said locking position of the chock members (6a, 6b), and that these means (7, 8) are configured to automatically return to said rest position by releasing the potential energy stored when the chock members (6a, 6b) are moved away from each other and from said locking position.