Abstract: A security barrier includes a horizontal composite beam extending across a roadway is mounted between vertical posts at either end of the beam. Hydraulic cylinders fastened at each beam end and to the vertical posts cause the beam to be raised and lowered, as needed. When the beam is at its lowest position, it allows for the normal flow of traffic over the top of the beam. When the beam is in its fully-raised position, it provides a vehicle barrier thirty-six inches above grade. A hydraulic power unit and components control the direction and speed of beam movement. The security barrier also includes electronic control and monitoring of the beam, and hydraulic system.