The height of the collision guardrails must accommodate the bridge clearances. Without collision guardrails, severe consequences could arise. If there are no collision guardrails on highways, it could lead to drivers not being able to drive in the correct direction. Collision guardrails are installed on both sides of the road to remind drivers of the edge lines; they are clearly visible during the day, but those who often drive at night will know that without collision guardrails, it could result in more and more severe accidents. The severity of traffic accidents would be greater without collision guardrails on highways.