A collapsible pedal box for an automobile is designed to collapse in the case of a frontal impact of the automobile, to reduce the risk of trapping the driver's feet. One or more pedals (13) are supported on a pivot shaft which is supported at its ends by pivot shaft supports (15,17) locked with respect to the side walls (1,3) of the pedal box that they are prevented from moving outwardly along an axis of the pivot shaft. Relative movement between the pedal box and another structural member within the driver's compartment in the case of a front-end impact causes first the unlocking and then the movement apart of the pivot shaft supports (15,17), and release of the pivot shaft and pedal assembly.