I'm thinking that whatever that thing is made of would be great for guard rails or parking barriers!
Actually, I disagree. It would give too much as a guardrail, thereby lowering the height of it and making it easier to fall over the top. That's a people guardrail.
As a roadside guardrail (implied by the parking barrier idea) I'm afraid it would act as a slingshot in a dynamic reaction to velocity (speed and direction). It would not be a head-on impact.
As a parking barrier, the speed would be less, but you'd still have to provide an ample buffer zone for the deflection caused by collision. The head-on impact would probably circumvent any sling-shot reaction.
But, that's all just speculation.