Abstract: An impact attenuator to absorb the impact energy of vehicle collisions. The attenuator includes a fiberglass shell which forms an interior cavity. Located within this cavity are a plurality of empty aluminum beverage cans. The cans are arranged in a three dimensional array having a number of horizontally planar rows. Each of the rows includes a plurality of columns, with each column being formed of a number of cans in end-to-end relation. The columns are aligned such that their longitudinal axes are parallel to the anticipated direction of impact, such that they will be forces to buckle under impact and thereby absorb a portion of the impact energy. The rows may each be placed in a tray-like divider having a peripheral lip to maintain the row's configuration. The entire array of cans may be surrounded by burlap to maintain the array configuration and prevent scattering of the cans after impact.