PURPOSE: To prevent a car body from overturning during turning at high speed and keep persons on the car from discomfort and smooth turning of the car body by connecting to a hydraulic device a hydraulic drive control device which is associated with a steering handle, and actuating a pair of right and left or front and rear hydraulic devices simultaneously and equally when the car is turned.

CONSTITUTION: When a car runs forward valve holes 15, 16 are located in respective positions 19, 20 indicated by the dotted lines and activity of hydraulic pressure is stopped. When a steering wheel is operated to e.g. the left as the car is turned, drive valves 13, 14 are rotated through gears 6, 7, 8 and the valve hole 15 is opened to a feed oil opening 23 and the valve hole 16 is separated from a feed oil opening 23. Pressure oil is forced to flow into a distributor 30 from the feed oil opening 23 through the valve hole 15 and a through hole 17 and is distributed at branch portions 33, 34 to the respective hydraulic cylinders 42 etc., of front and rear wheel portions. For example, the pressure oil flows into the hydraulic chamber 44 of the front wheel portion as indicated by the arrow E, thereby thrusting a piston 43 down. This action occurs simultaneously and equally at the front and rear wheel portions. The body of the car is thereby slanted.