This report evaluates whether a clear correlation between guardrail height and penetration of the guardrail exists in the collision and roadside features inventory datasets available for Washington State. In particular, do guardrail heights of 27 inches or lower experience more through, over, or under penetrations (TOU) than 28 inch or greater guardrail installations?
Washington (State) Dept. of Transportation. Design Policy, Standards & Research Team
Guardrails, Height, Physical properties, Collisions.