These barriers are typically made from galvanized steel, designed to withstand significant impact. The most common type is the W-beam barrier, which has a "W" shaped cross-section that allows it to absorb and dissipate the kinetic energy of a collision. The barrier works by deforming upon impact, gently slowing and redirecting the vehicle back onto the road, which helps to minimize damage to the vehicle and reduce the severity of injuries to its occupants.