For the road traffic science, see various articles under . Road traffic control involves directing vehicular and pedestrian traffic around a construction zone, accident or other road disruption, thus ensuring the safety of emergency response teams, construction workers and the general public. Traffic control also includes the use of CCTV and other means of monitoring traffic by local or state roadways authorities to manage traffic flows and providing advice concerning traffic congestion. Traffic Control Technicians (TCT's) or Traffic Control Supervisors (TCS's) are often known as "lollipop men" (usually this name only applies to TCT's working near schools to aid pupils in road crossing) from the appearance of their Stop/Slow signs, known as "Stop bats". Road Traffic control is an outdoors occupation, night or day for long hours in all weathers, and is considered a dangerous occupation due to the high risk of being struck by passing vehicles. Safety equipment is vitally important. Fatigue is a big issue, as tired TCT's may forget to watch their traffic, or may inadvertently turn their "Stop bats" to the "Slow" position. Many drivers are annoyed by the disruption to their route, and some are sufficiently antisocial as to aim at traffic controllers. Other drivers simply don't pay enough attention to the road, often from using their mobile (cell-) phones, or because they are tired from a night shift at work. Not a few are exceeding the posted speed limit. Typically, a worksite will be set up with warning signage well in advance of the actual work area. This may involve (in Australia) "Roadworks Ahead", temporary speed restrictions, "Worker Symbolic" (a stylized workman with a pile of rubble, black silhouette on a retroflective orange background), "Reduce Speed", "Lane Status" boards (indicating that some lanes on a multilane roadway will be closed), "Prepare to Stop" and advisory signs telling what is happening (e.g. Water Over Road, Trucks Entering, and Power Line Works Ahead).