The proto type Jersey barrier was created by the NJ Dept of Highways-- to discourage NJ drivers from having head on meetings in the middle of some of NJ's older roads..
they were designed to be effective at preventing vehicles that hit them from going over them.. if hit sideways, the gentle ramp at the bottom is designed to lead you back into your lane.. but the angle of incline chages at about 8 inches, and becomes steeper.. this is designed to stop or (worst case) flip a vehicle over.. (thus limiting the injures to only the passengers in one vehicle.)
they have other names.. i vaguely remember the scene in the movie "volcano" set in LA, the la brea tar pits starts spewing out lava.. to stop the lava flow, the FEMA guy calls for ???(K bar?).. what ever.. what he wanted, and got was Jersey barriers
