arrest vehicles on either side of a barrier they additionally may be reset for reuse relatively rapidly following deployment application_number US 27285608 A description depicted in fig1 and 2 a b is exemplary system 10 of the present invention system 10 is denoted u201c in ground u201d because many of its components are below grade at least prior to deployment those skilled in the relevant field will recognize that not all components of system 10 need necessarily be below grade prior to deployment so system 10 may be constructed differently than as shown in fig1 and 2 a c nevertheless system 10 preferably includes module 14 which beneficially may be a pre cast block or beam of concrete module 14 typically will be elongated with a length greater than the width of the roadway runway or other travel surface with which it is deployed when positioned across such travel surface therefore module 14 will span its width module 14 additionally is designed to be embedded in the travel surface with its upper surface 18 flush therewith upper surface 18 itself thus may form part of the travel surface accordingly module 10 should be of sufficient strength to bear loads consistent.