The present invention relates to posts, carriages, methods of manufacturing the components and their assembly into a barrier. The invention also includes a Z post attachment includes an attachment tab 8.016 and end engagement flange 8.024, 8.026 adapted to engage the end of the post. The arrangement can include a delineator 8.030 which is skew in relation to the tab 8.016, so as to provide reflector faces 8.032 which face oncoming traffic.