The invention concerns a vehicle whereof the rigid body (1, 2, 4) comprises the front element (20) forming the rear element of a deformable articulated quadrilateral (17, 18, 19, 20). The element (17) is mounted in the extension of the arm (15) linked to the wheel of the front axle (7). The undercarriage comprises on the right two tandem wheels (9 and 10) whereof the arms are articulated on the system (24, 26) pivoting on the pivots (27) relative to the pillar (28) integral with the body. On the left the undercarriage is completed by a symmetrical arrangement. The rear wheel (14) is linked to the body by the yoke (30), the support (29) and the strut (4).