Abstract: A vehicle barrier including a housing located in a pit, a barrier pivotally mounted on the housing and having a roadway surface and a barrier surface, hydraulic motors for moving the barrier from a retracted position where said roadway surface lies substantially flush with the roadway to an extended position where the barrier surface obstructs a vehicle on the roadway, energy absorbing members in the barrier, a break-away member effectively located between the barrier and the housing for permitting the barrier to pivot beyond its normal extended position when subjected to a vehicular impact above a predetermined value to thereby lift a vehicle off of the ground and throw it upwardly, and self-aligning structure between the barrier and the housing for effecting engagement between the hydraulic motors and the barrier upon installing the barrier into the housing.