Described herein is a fluid device for the recovery of the kinetic energy of land vehicles, comprising an intake line, a delivery line, and a pumping unit, which is connected to the intake line and to the delivery line, and at least one actuating element set along a street or railroad course of an infrastructure for the transit of vehicles, functionally connected to the pumping unit and mobile between a position of unloading and a position of loading, in which the actuating element is designed to be surmounted by a vehicle travelling along the street or railroad infrastructure.