W Beam Crash Barrier is designed to withstand the impact of vehicles of certain weights at a certain angle while traveling at the specified speed. They are expected to guide the vehicle back on the road while keeping the level of damage to the vehicle as well as to the barriers within acceptable limits. Ideally, a crash barrier should present a continuous smooth face to an impacting vehicle, so that the vehicle is redirected, without overturning, to a course that is nearly parallel to the barrier face and with a lateral deceleration, which is tolerable to the motorist. To achieve these aims the vehicle must be redirected without rotation about both its horizontal or vertical axis (that is, without ‘spinning out’ or overturning), and the rate of lateral deceleration must be such as to cause the minimum risk of injury to the passengers.