Crash attenuator guardrail apparatus includes an impact head and a backstop having a cable and guardrails supported by guardrail supports located between the impact head and the backstop. Frictional forces are applied to the cable to control and resist movement of the impact head toward the backstop and provide lateral resistance. The guardrail supports include a base having break away structure and brace members having bends and which shorten or lengthen to absorb energy resulting from vehicle impact.