Apparatus and methods are described for preventing the penetration of vehicles by narrow objects such as guardrail ends or portions of a guardrail end treatment during a collision. In one embodiment, portions of an ET-2000 guardrail extruder terminal are adapted for improved operation during impacts by attachment of a penetration guard. The penetration guard may also be affixed to other guardrail end treatments or even other suitable highway objects to create an improved safety apparatus. The penetration guard includes a frame and is affixed to the impact head of an ET-2000 guardrail extruder terminal. The frame is greatly collapsible when impacted from a substantially end-on direction. However, when impacted from a direction other than sub...