Following the recent terrorist attacks, the obligations that event organizers shall comply with, have changed and increased in order to protect participants from vehicles that can throw themselves into the crowd.
Hence, the intensification of these cases around the world forces organizers to delimit the spaces intended for the event with real road bollards.
Until now the only usable device was the so-called New Jersey barrier, that is a row of bulky concrete blocks that were positioned in the middle of the roadway to reduce the speed of the vehicles that intended to enter the event (while a space between the blocks let police and rescue vehicles pass).
Today that device, so heavy, unsightly and expensive in terms of both economics and workforce, is supplanted by the Anti-Terrorism Barrier.