It is mainly installed between guardrail and post to reduce the crash collision of highway/expressway/roadway.Bock itself is an energy absorbing part,so it could make theguardrail deform gradually during the sudden collisions.thus is conducive to energy absorption, reduce occupant casualties;at the same time,the block could allocate the crash energy to guardrail and post,thereby increase the overall strength and tension of the guardrail system.