Oldcastle Materials and ARTIS, LLC have joined forces to develop an innovative work zone intrusion detection and alarm system. This system has been named AWARE, for Advance Warning And Risk Evasion. Unlike previous intrusion alarm systems that rely on the detection of vehicles crossing a predetermined perimeter (typically identified with pneumatic tubes or infrared beams), this new system utilizes a target threat detection and tracking methodology to logically assess approaching vehicle speed, location, and possible trajectory. This study was conducted to assess performance of the AWARE intrusion alarm system in a closed course environment. This testing was intended to verify that the alarm system does produce the proper alert when conditions warrant (i.e., lights activate and do so when the approaching vehicle is at the appropriate distance based on the threat detection and SSD algorithms). In addition, the testing was also intended to verify that alerts were not activated when conditions did not warrant (i.e., that the system does not produce a false alarm). The performance of the Worktrax devices designed to be worn by field personnel and activated when an intrusion threat is detected was also evaluated. These devices were positioned at the AWARE system vehicle and at locations upstream of the vehicle to assess the ability of the system to correctly determine the location of the devices and their position relative to the intrusion threat. AWARE systems were tested under two basic operating modes: lane closures and flagging operations. For testing purposes, right lane closures were created for three different scenarios:
- Lane closure in a tangent alignment
- Lane closure in right curve alignment
- Lane closure in a left curve alignment
A flagging operation on a two-lane, two-way highway was also created. A number of approach vehicle trajectories were developed and performed under both operating modes to verify that the system activated when appropriate and did not activate when not appropriate. Several of these trajectories were performed using two different vehicle types, approach speeds, and slightly different alarm orientations relative to the direction of traffic flow. Based on this methodology, the system achieved a 100 percent success rate in terms of correctly activating or not activating the warning lights and audible alarm across the range of scenarios and vehicle trajectories tested. Similarly, the Worktrax devices achieved a 97 percent success rate measured across the range of device locations, test scenarios, and vehicle trajectories. However, it was determined that all of the unsuccessful events for the Worktrax device were attributable to the test protocol exceeding the effective communication range of the intrusion detection system with the Worktrax device. Ongoing improvements in the device are expected to significantly increase this communication range. All other device locations, scenarios, and trajectories tested achieved a 100 percent success rate.