A guardrail, also known as a crash barrier or safety barrier, is a protective barrier designed to prevent vehicles from straying off the road or colliding with obstacles. Guardrails are commonly used on roads and highways, as well as on bridges and in parking lots, to help ensure the safety of drivers and passengers.
Guardrails are typically made from materials such as steel, aluminum, or concrete, and they can be either rigid or flexible, depending on the specific application and the desired level of impact resistance. The most common type of guardrail is the W-beam guardrail, which consists of a series of steel posts supporting a horizontal steel rail in the shape of a "W".