The barriers could be used to surround the whole road work site, or just direct incoming traffic.

The water filled barriers protect both drivers and construction workers and equipment. The barriers can be used at any roadwork both as a barrier for protection and to signal drivers that this is an active workplace.

Some drivers do not slow down when approaching a road work until the last second, thus creating hazardous conditions for construction workers. When barriers are present we see have seen drivers lowering their speed significantly in advanced,  compared to just posted speed limits or traffic cones.