Rear underride crashes are responsible for thousands of deaths every year in Brazil. To support the fight against this calamity, it was design and tested an articulated guard able to avoid car underride. Because of its articulation capability, this guard can be placed as low as necessary without impairing the truck maneuverability. Crash tests were carried out with the new guard and with another one constructed according to Brazilian standards. The articulated guard was able to avoid underride of a vehicle GM Corsa colliding at 50 km/h in offset of 50%. The other guard could not avoid underride under the same test conditions.