After testing two models of the work zone intrusion alarm, Vermont DOT’s research unit purchased a model that uses an infrared beam sent from a transmitter unit to a receiver unit that also houses the siren. When a vehicle breaks this beam, the siren goes off. The research unit picked this model because it was the fastest and easiest to set up.
The work zone intrusion alarm’s first application in Vermont was in early 1995, when a bridge deck condition survey closed one of the bridge’s two lanes to traffic. When vehicles tripped the alarm, the siren was more than loud enough to be heard over the generator and other equipment at the work site. Since then, the research unit has used the intrusion alarm at nearly a half-dozen work zones.
The intrusion alarm is best suited for certain projects, according to Allan Schneck of Vermont AOT. "When we have day-long or shorter projects, this equipment is very useful," he says. Because the research unit sends out very small teams, he explains, itState/Agency: Vermont
Where Documented: Case study titled "Alarm System Improves Safety in Work Zones"
Topics: Intrusion Alarms