Hydraulic rising bollards are designed especially for high security vehicle entrances and for a location that has to be closed for motorized traffic on specific times. They can be installed as a single unit as well as in groups. Bollards are driven hydraulically and the hydraulic drive unit is placed in an installation cabinet close to the bollards. In case of power failure bollards can be lowered manually. With the help of plc/microprocessor controlled electronics, raise/lower function can be achieved by every kind of card readers, biometric readers like fingerprint or hand shape, radio control, on/off switch or key switch etc. Besides, safety accessories like loop detectors, photocells, flashing lights or red/green lights can be integrated to the control electronics very easily.